19 September 2005

Burren Energy Plc

(“Burren” or “the Group”) Interim Results for the six months ended 20 June 2005

Burren Energy [LSE:BUR], the independent oil and gas exploration and production company, today announces its interim results for the six months ended 30 June 2005. These interim results are prepared under International Financial Reporting Standards (IFRS). All comparisons are based on an IFRS restatement of UK GAAP financial information for the first six months of 2004, the reconciliation of which is included in this statement. The Group has adopted US dollars as its reporting currency with effect from 2005.

In a separate announcement, Burren today announced the results of 4 development wells drilled on the M’Boundi field during August and September 2005.

Highlights

Financial Highlights

• Turnover up by 166% to US$168.1 million (H1 2004 : US$63.1 million)

• Pretax profit up by 388% to US$97.2 million (H1 2004 : US$19.9 million)

• Profit after tax up by 575% to US$82.9 million (H1 2004 : US$12.3 million)

• Basic earnings per share up by 564% to US cents 59.9 (H1 2004 US cents 9.0)

• Net cash from operating activities up by 179% to US$108.6m (H1 2004 : US$38.9m)

• Operating cost per bbl* down to US$2.55 / bbl (H1 2004 : US$2.90 / bbl)

• Interim dividend of 2.5 pence per share (H1 2004 : Nil) * working interest basis

Operating Highlights

• Average production up by 95% to 29,100 bopd (H1 2004 : 14,960 bopd) on working interest basis and by 90% to 22,200 bopd (H1 2004 : 11,710 bopd) on entitlement basis

• 24 new development wells in Turkmenistan and Congo on production since January

• Current working interest production over 34,000 bopd following recent M’Boundi drilling success.

• Interpretation of recently acquired 2D and 3D seismic in Turkmenistan and Congo well under way, anticipating the start of exploration drilling in Q4

Corporate Highlights

• 8 year extension of M’Boundi development licence as part of farm-in by Congo state-owned oil company (subject to government ratification)

• Signature of North Hurghada Marine concession agreement in Egypt

• Acquisition of 26% interest in Hindustan Oil Exploration Company (HOEC)

Finian O’Sullivan, Chief Executive Officer, commented:

“The first half of 2005 has proved to be a record period for us, with profits after tax up nearly six-fold. Pleasingly, we have also almost doubled production to 22,200 bopd, on an entitlement basis, whilst reducing the operating cost per production barrel to one of the lowest levels amongst our peers. Our record of production growth through field development activity will continue. Over the next year we will participate in 18 exploration wells along the trend of our proven hydrocarbon systems. Together, these drilling programmes will demonstrate the full value of our assets.”

Analysts Presentation At 9.30 am (BST) the Company will be holding an Interim Results presentation for analysts at the offices of Pelham PR: No 1 Cornhill, London, EC3V 3ND Webcast and Conference Calls In conjunction with the Company's Interim Results presentation for analysts in London there will be a simultaneous conference call and webcast. Participants will be able to view the Interim Results presentation via the company website: www.burren.co.uk 9.30 am (BST): Conference Call – Please call +44 (0) 20 8901 6985. A replay facility will be available from one hour after the conference call for 24 hours. To access the replay facility please call +44(0)20 8515 2499. The passcode is 677470#. 9.30 am (BST): Webcast - Please visit: http://www.investorcalendar.com/IC/CEPage.asp?ID=94984 An archive of the Webcast will be available from this afternoon. Enquiries: Burren Energy Tel : 020 7484 1900 Finian O’Sullivan, Chief Executive Officer Andrew Rose, Chief Financial Officer www.burren.co.uk Pelham PR Tel: 020 7743 6676 James Henderson Alisdair Haythornthwaite EDITORS NOTES Burren Energy is an independent oil and gas exploration and production group, headquartered in London. It is focused on four principal regions: the Caspian region of the former Soviet Union, West Africa, North Africa and through a strategic investment stake in the Hindustan Oil Exploration Company, India.

Chairman’s Statement Burren’s results for the first half of 2005 were extremely strong, driven by a combination of rising oil prices and sharply higher production. After tax profits reached US$ 82.9 million, up nearly six-fold on the first half of 2004 and comfortably ahead of the full year 2004 figure, and earnings per share grew by 564% to US 59.9 cents (H1 2004 : US 9.02 cents). The company is declaring an interim dividend of 2.5 pence per share, which compares with 3.0 pence per share paid in respect of the full year 2004. Average production on a working interest basis increased by 95% to 29,100 bopd and on an entitlement basis by 90% to 22,200 bopd. Of note is the fact that our operating cost per production barrel has continued to reduce : for the first half it was US$ 2.55 / bbl compared with US$ 2.90 / bbl in the first half of 2004 (both figures on a working interest basis). We have made material progress in developing our two core assets, having since January completed and brought on production 24 development wells, 11 in Turkmenistan and 13 in Congo, taking group working interest production from 26,450 bopd in January to over 34,000 bopd at the present time. The interpretation of the 3D seismic data acquired in Turkmenistan and Congo is well under way and we expect to be identifying targets for drilling in the fourth quarter. I was also delighted to see the pleasing results from the development drilling programme on the M’Boundi field in Congo announced today. In Egypt we have signed our second concession agreement, North Hurghada Marine, and expect to commence drilling on our existing East Kanayis block in December. In February of this year Burren made an initial acquisition of a 26% shareholding in Hindustan Oil Exploration Company (“HOEC”), which represented an attractive opportunity to enter the Indian oil and gas industry. This initial investment has already shown a significant return, increasing in market value from US$26 million to US$60 million. The mandatory open offer for a further 20% of equity in HOEC, which this purchase triggered, has now concluded with no material take up : a result which was expected given that the offer price was fixed back in February. Now that the open offer has expired Burren can move forward in supporting HOEC technically and financially to achieve its key objective of developing the PY-1 gas field, where it is intended to reach first production by the 2nd quarter of 2007. Burren continues to view India as affording significant opportunities in oil and gas, and we maintain our original objective of seeking ways to acquire up to 51% of HOEC but only at an acceptable price. In August we announced that Burren and the operator, Maurel & Prom, had entered into a conditional agreement for SNPC, the Congolese state oil company, to acquire an interest in the M’Boundi field and Kouilou exploration area in return for (inter alia) an 8 year extension of the M’Boundi development licence. The agreement, which has yet to be completed, may not become effective before the end of this year : until this time our interest in the asset remains at 35%. Burren believes that there is significant value to be generated from the extension of the M’Boundi licence as and when expected increases in the field area and enhanced recovery rates from water injection become a reality. Additionally we believe that the adjacent Noumbi licence, ratification of which is a condition of the deal with SNPC, offers exciting exploration possibilities. Activity by area is described in more detail below. Turkmenistan Working interest production increased by 50% year on year in the first half of 2005, averaging 15,150 bopd (H1 2004 : 10,100 bopd). In the year to date 12 development wells have been drilled, 7 shallow and 5 deep. Working interest production is currently 15,650

bopd. We expect to drill one further deep development well before moving our existing rig on to spud the first of a series of exploration wells to the east of the Burun field before the end of the year. A new drilling rig, capable of handling higher pressure exploration wells, is now on course to arrive in December following completion of its current assignment, and will join the exploration programme beginning with a well on the south flank of the Burun field. A third drilling rig is in the process of being sourced. Interpretation of the 540 sq km of 3D Seismic acquired over the Nebit Dag PSA area outside the Burun field is nearing completion, and we are in the process of finalising sites for 2006 exploration drilling in the fourth quarter. Investment in production facilities has continued, with two additional gas compressors being installed and a further two due to arrive later this year. A pilot 5,000 bwpd water injection project is also expected to start up by year end. Congo In the first six months of 2005 Congo working interest production increased by 187% year-on-year, averaging 13,950 bopd (H1 2004 : 4,900 bopd). There are now 4 rigs operational on the M’Boundi field, having drilled and completed 17 wells in the year to date of which all but 3 have been (or will shortly be) placed on production. As a result of 4 recent successful wells M’Boundi production currently stands at over 52,000 bopd gross, or 18,200 bopd attributable to Burren’s 35% working interest, from 34 wells. We expect up to 8 further wells to be drilled and completed during 2005, making a total of 25 for the year. The Kouakouala field is producing at 1,300 bopd gross (325 bopd attributable to Burren’s 25% working interest) with no further drilling activity planned. Work is under way to expand the M’Boundi processing capacity from 60,000 bopd to 90,000 bopd and a pilot 20,000 bwpd water injection scheme is scheduled to be operational in the second quarter of next year. Drilling targets on the potential extensions to the M’Boundi field and elsewhere in the Kouilou licence area will be agreed in the fourth quarter of this year upon completion of the 3D and 2D seismic interpretation, with drilling expected to commence towards the end of the year. Egypt A provisional drilling programme of three shallow Cretaceous wells and a deeper Jurassic well on the East Kanayis concession (Burren 100% working interest) has been drawn up. A rig has now been secured (subject to final EGPC approval)and should be mobilising in November, later than we had envisaged owing to the acute competition for rigs in Egypt. Tenders are in progress for new 2D and 3D seismic to improve our knowledge of the deeper Jurassic level where there is potential for gas-condensate accumulations. The concession agreement for North Hurghada Marine offshore licence was signed in August and data collection has commenced. It is planned to shoot 2D and 3D seismic in the first quarter of 2006 subject to vessel availability. Parliamentary approval for the North Lagia Concession is anticipated later this year. India (HOEC : Burren 26%) HOEC declared a profit after tax of Rs. 385 million (US$8.6 million) for the year ended 31 March 2005, compared with Rs. 221 million (US$4.8 million) for the previous year. Burren’s 26% share of HOEC’s profit between acquisition and 30 June 2005 was Rs. 21 million

(US$0.5 million). Average gross production over the year from the PY-3 oil field, the company’s principal current source of cash flow, increased by 53% to 6,269 bopd (4,108 bopd in the 2003/4 financial year). HOEC continues to work towards securing the financing for its major PY-1 gas development. Shipping Shipping has performed well in the first six months of the year and shown a small gross profit compared with a loss in both halves of 2004. Financial results The results for the period have been prepared for the first time under International Financial Reporting Standards (“IFRS”) and also in US dollars, which is the functional currency of the group and which has been adopted as the reporting currency with effect from 2005. Comparative financial information for the first six months of 2004 has been restated according to IFRS in US dollars. The revenue growth of 166% to US$168.1 million (H1 2004 : 63.1 million) stemmed from the twin drivers of increased sales volumes and higher oil prices. Entitlement production grew by 90% to 22,200 bopd (H1 2004 : 11,710 bopd), but in Nebit Dag an underlift of 255,000 bbls had developed by period end so the average group sales volume was only 20,310 bopd. Had these barrels been lifted at the average realised price for Nebit Dag crude, revenues would have increased by US$11.6 million and pretax profit by US$9.9 million. The average realised oil price (before losses on oil price derivative contracts) in the period was US$43.9 compared with US$29.7 in H1 2004. Cost of sales rose by 75% to US$63.5 million (H1 2004 : US$36.3 million). Within cost of sales, losses on oil price derivatives amounted to US$14.3 million in the period. Of these US$9.6 million were realised losses, representing 2,740 bopd hedged under a Brent price collar with a cap of US$30.2, and US$4.7 million were unrealised losses arising from the mark-to-market of outstanding contracts at the period end. These outstanding contracts all expire by the end of 2005. Depreciation tripled to US$32.0 million (H1 2004 : US$10.6 million) as production volumes increased and higher depreciation rates per barrel were applied, but administrative expenses were down slightly at US$6.4 million (H1 2004 : US$6.6 million). Pretax profit increased by 388% to US$97.2 million (H1 2004 : US$19.9 million). Higher current and deferred tax charges in Turkmenistan caused the tax charge to rise to US$14.2 million (H1 2004 : US$7.7 million), leaving after tax profits up by 575% to US$82.9 million (H1 2004 : US$12.3 million). Operating cash flow rose by 179% to US$108.6 million (H1 2004 : US$38.9 million), after a US$20.5 million increase in working capital arising from the increased sales revenues over the period. Total investment, including the purchase of 26% of HOEC and the US$25.1 million of cash placed in a blocked escrow account to back the open offer, was US$136.1 million, leading to a net outflow before financing of US$27.5 million. Given the negligible take up of the open offer substantially all of the US$25.1 million escrow account monies will be released back to Burren shortly. Excluding India, capital expenditure was US$85.0 million. Health Safety Environment & Community (“HSEC”) With the assistance of external consultants Burren is developing an enhanced set of HSEC policies and key performance indicators against which the company will report with effect

from 2005. Burren’s safety record in the year to date has been excellent, with no serious incidents reported. Outlook Going forward through 2006 Burren will continue to develop its core assets. We expect group working interest production to reach 37,000 bopd at year-end 2005, giving an average working interest production for the year as a whole of some 31,000 bopd, although entitlement production for the year as a whole is not expected to exceed the figure for the first half of the year owing to the effect of high oil prices on the M’Boundi entitlement barrels under the PSA terms. Despite this entitlement effect the current strong oil price will lead to a substantial increase in profit for the year as a whole compared with 2004. The focus of Burren’s activity over the remainder of 2005 and in 2006 will increasingly be the exploration drilling programmes in Turkmenistan, Congo and Egypt. Commencing in the fourth quarter two large rigs will be dedicated to continuous drilling in Turkmenistan, where we expect to drill a minimum of 8 deep wells over the period to end 2006. In Congo we expect to drill a similar number of wells, and in Egypt we anticipate some 4 wells over the period. By the end of 2006 we expect to have up to 6 rigs engaged in exploration drilling and to have drilled nearly 20 exploration wells in all. Preliminary prospects identified for this drilling amount to some 750 million bbls of estimated potential gross field reserves (490 million bbls on a working interest basis). This exploration is underpinned by solid production which is fully benefiting from current high oil prices. The future looks exciting and I look forward to the rest of the year with confidence. Brian Lavers Chairman 19 September 2005

Production Summary

bopd Current H1 2005 average

H1 2004 average

H1 y/y increase

TurkmenistanGross Field 19,500 19,000 14,180 34%Working Interest * 15,650 15,150 10,100 50%Net Entitlement n/a 12,300 8,210 50%

CongoGross Field 52,480 40,370 14,070 187%Working Interest 18,230 13,950 4,860 187%Net Entitlement n/a 9,910 3,470 186%

Group TotalGross Field n/m n/m n/m n/mWorking Interest 33,880 29,100 14,960 95%Net Entitlement n/a 22,210 11,680 90%

* excludes Initial Oil to which Turkmenneft is entitled

Independent Review Report to Burren Energy Plc

Introduction

We have been instructed by the Company to review the consolidated financial information for the six months ended 30 June 2005 and the six months ended 30 June 2004 which comprises the Group income statement, Group statement of total recognised income and expense, Group statement of changes in shareholders’ equity, Group balance sheet, Group cash flow statement and related notes 1 to 11. We have read the other information contained in the interim report and considered whether it contains any apparent misstatements or material inconsistencies with the financial information. This report is made solely to the Company in accordance with Bulletin 1999/4 issued by the Auditing Practices Board. Our work has been undertaken so that we might state to the Company those matters we are required to state to them in an independent review report and for no other purpose. To the fullest extent permitted by law, we do not accept or assume responsibility to anyone other than the Company for our review work, for this report, or for the conclusions we have formed.

Directors' responsibilities

The interim report, including the financial information contained therein, is the responsibility of, and has been approved by, the directors. The directors are responsible for preparing the interim report in accordance with the Listing Rules of the Financial Services Authority and the requirements of International Accounting Standard 34 ‘Interim Financial Reporting’ (“IAS 34”) which require that the accounting polices and presentation applied to the interim figures are consistent with those applied in preparing the preceding annual accounts except where any changes, and the reasons for them, are disclosed. International Financial Reporting Standards As disclosed in note 1, the next annual financial statements of the Company will be prepared in accordance with International Financial Reporting Standards as adopted for use in the EU. Accordingly, the interim report has been prepared in accordance with IAS 34 and the requirements of International Financial Reporting Standard 1, ‘First Time Adoption of International Financial Reporting Standards’ relevant to interim reports.

Review work performed

We conducted our review in accordance with the guidance contained in Bulletin 1999/4 issued by the Auditing Practices Board for use in the United Kingdom. A review consists principally of making enquiries of Group management and applying analytical procedures to the financial information and underlying financial data and, based thereon, assessing whether the accounting policies and presentation have been consistently applied unless otherwise disclosed. A review excludes audit procedures such as tests of controls and verification of assets, liabilities and transactions. It is substantially less in scope than an audit performed in accordance with International Standards on Auditing (UK and Ireland) and therefore provides a lower level of assurance than an audit. Accordingly, we do not express an audit opinion on the financial information.

Review conclusion

On the basis of our review we are not aware of any material modifications that should be made to the financial information as presented for the six months ended 30 June 2005 and the six months ended 30 June 2004.

Deloitte & Touche LLP Chartered Accountants London 19 September 2005 Notes: A review does not provide assurance on the maintenance and integrity of the website, including controls used to achieve this, and in particular on whether any changes may have occurred to the financial information since first published. These matters are the responsibility of the directors but no control procedures can provide absolute assurance in this area. Legislation in the United Kingdom governing the preparation and dissemination of financial information differs from legislation in other jurisdictions.`

Group Income Statement Unaudited Unaudited Audited

6 months to 6 months to Year ended

30 June 30 June 31 December

2005 2004 2004

NOTES US$’000 US$’000 US$’000

REVENUE 2 168,080 63,078 185,787 Cost of sales (63,492) (36,300) (87,866) GROSS PROFIT 104,588 26,778 97,921 Administrative expenses (6,432) (6,593) (10,723) Other operating expenses (523) - (12) Share of associate’s profit 6 483 - - OPERATING PROFIT 98,116 20,185 87,186 Interest and investment income 394 278 678 Finance costs (1,330) (533) (1,709) PROFIT ON ORDINARY ACTIVITIES BEFORE TAX 97,180 19,930 86,155

Tax on profit on ordinary activities 5 (14,249) (7,650) (17,748) PROFIT ATTRIBUTABLE TO EQUITY HOLDERS OF PARENT COMPANY 82,931 12,280 68,407

Dividends declared 9 (7,550) - -

RETAINED PROFIT FOR THE PERIOD 75,381 12,280 68,407

Earnings per ordinary share – basic (US cents) 3 59.9 9.0 50.1 Earnings per ordinary share – diluted (US cents) 3 57.9 8.6 47.9

Group Statement of Total Recognised Income and Expense

Unaudited 6 months to

Unaudited 6 months to

Audited Year Ended

30 June 30 June 31 December

2005 2004 2004

NOTES US$’000 US$’000 US$’000 Exchange differences on translation of

subsidiaries and associates (237) 20 188 Net (loss)/income recognised directly in

equity (237) 20 188

Profit for the period 82,931 12,280 68,407Total recognised income and expense for the period 82,694 12,300 68,595 Group Statement of changes in Shareholders’ Equity

Share capital

US$’000

Share premium

account US$’000

Re-valuation

reserve US$’000

Other Reserve US$’000

Merger Reserve US$’000

Shares to be issued US$’000

Profitand loss account

US$’000 Total

US$’000 At 1 January 2005 45,419 87,409 27,295 3,096 (12,716) 4,364 107,893 262,760 Retained profit for the period - - - - - - 75,381 75,381 Shares issued in the period 712 857 - - - - - 1,569 Transfer of additional

depreciation on revalued assets

-

-

(717) - -

- 717 -

Deferred share awards - - - - - 524 - 524 Exchange adjustments - - - - - - (237) (237)

At 30 June 2005 46,131 88,266 26 578 , 3,096 (12,716) 4,888 183,754 339,997

Share capital

US$’000

Share premium

account US$’000

Re-valuation

reserve US$’000

Other Reserve US$’000

Merger Reserve US$’000

Shares to be issued US$’000

Profitand loss account

US$’000 Total

US$’000 At 1 January 2004 44,695 87,050 28,805 3,096 (12,716) 20 36,728 187,678 Retained profit for the period - - - - - - 12,280 12,280 Shares issued in the period 718 295 - - - - - 1,013 Transfer of additional

depreciation on revalued assets

-

-

(1,022) - -

-

1,022 - Deferred share awards - - - - - 4,105 1,061 5,166 Exchange adjustments - - - - - - 20 20

At 30 June 2004 45,413 87,345 27 783 , 3,096 (12,716) 4,125 51 111 , 206,157

Group Balance Sheet

Unaudited

30 June Unaudited

30 June Audited

31 December 2005 2004 2004 NOTES US$’000 US$’000 US$’000 ASSETS Non-current assets Intangible assets other than goodwill 10,341 5,620 8,381Property, plant and equipment 285,732 203,535 253,826Investment in associate 6 26,094 - - 322,167 209,155 262,207 Current assets Inventories 1,283 931 1,015Trade and other receivables 7 85,522 17,001 37,673Cash and cash equivalents 24,678 34,650 39,962 111,483 52,582 78,650 Total assets 433,650 261,737 340,857 LIABILITIES Current liabilities Trade and other payables (38,928) (24,389) (43,600)Fair value of derivatives (15,172) (13,027) (10,528)Short term borrowings (10,695) (663) (580) (64,795) (38,079) (54,708) Non-current liabilities Borrowings (5,615) (6,312) (4,121)Provision for deferred tax (23,243) (11,189) (19,268) (28,858) (17,501) (23,389) Total liabilities (93,653) (55,580) (78,097) NET ASSETS 339,997 206,157 262,760 EQUITY Called up share capital 46,131 45,413 45,419Share premium account 88,266 87,345 87,409Other reserves 3,096 3,096 3,096Merger reserve (12,716) (12,716) (12,716)Revaluation reserve 26,578 27,783 27,295Shares to be issued 4,888 4,125 4,364Profit and loss account 183,754 51,111 107,893 TOTAL EQUITY 339,997 206,157 262,760

Group Cash flow Statement

Unaudited

6 months to Unaudited 6 months to

Audited Year ended

30 June 30 June 31 December 2005 2004 2004 US$’000 US$’000 US$’000 OPERATING ACTIVITIES Cash flow generated by operations 4 110,251 38,945 100,177 Taxation paid (1,628) - (130) NET CASH FROM OPERATING ACTIVITIES 108,623 38,945 100,047 INVESTING ACTIVITIES Purchases of intangible fixed assets other than goodwill (1,959) (1,829) (4,591) Purchases of property, plant and equipment (83,005) (40,842) (87,347) Investment in associate 6 (26,010) - - Deposit in blocked account (25,130) - - NET CASH USED IN INVESTING ACTIVITIES (136,104) (42,671) (91,938) FINANCING ACTIVITIES Interest received 485 278 589 Interest paid (615) (409) (565) Arrangement and facility fee - - (518) Interest element of finance lease rentals (617) - (620) Issue of ordinary share capital 1,569 1,013 1,083 Receipt from loans 15,000 360 360 Repayment of loans (3,200) - (4,501) Capital element of finance lease rentals (192) - (3,809) NET CASH PROVIDED BY/ (USED IN) FINANCING ACTIVITIES 12,430 1,242 (7,981) NET (DECREASE)/ INCREASE IN CASH AND CASH EQUIVALENTS (15,051) (2,484) 128

CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD 39,962 37,123 37,123 Effect of foreign exchange rate changes (233) 11 2,711

CASH AND CASH EQUIVALENTS AT END OF PERIOD 24,678 34,650 39,962

Notes to the Interim Report For the six months to 30 June 2005 1. Basis of Preparation In 2004 the Group prepared its consolidated financial statements under UK generally accepted accounting principles (“UK GAAP”). The full accounts for the year ended 31 December 2004, which received an unqualified report from the auditors and did not contain a statement under section 237(2) or (3) of the Companies Act 1985, have been filed with the Registrar of Companies. On 1 January 2005, in accordance with European law, the Group adopted International Financial Reporting Standards (“IFRS”). This interim financial report has therefore been prepared using accounting policies that the Group believes will comply with IFRS, in so far as they are likely to be codified and endorsed by EU member states for the full year, including IAS 34 “Interim Financial Reporting”. These accounting policies, together with the Group’s IFRS restated financial information for the year ended 31 December 2004 were published by the Company on 30 August 2005 and are available on the Company’s website on www.burren.co.uk. A restatement of the Group’s results for the 6 months ended 30 June 2004 under IFRS is provided in note 11. The interim financial information for the 6 months ended 30 June 2004 and 30 June 2005 is unaudited and does not constitute statutory accounts as defined in section 240 of the Companies Act 1985. The auditors have carried out a review of the financial information for these periods and their report is included as part of this announcement. This interim report was approved by the Board of Directors on 16 September 2005. 2. Segmental Analysis 6 months ended 30 June 2005 Analysis by activity Upstream Shipping Total US$’000 US$’000 US$’000Turnover 161,324 6,756 168,080Segment gross profit 104,368 220 104,588 WestAnalysis by geographical area Caspian Africa Total US$’000 US$’000 US$’000Turnover 95,152 72,926 168,080Segment gross profit 64,589 39,999 104,588 6 months ended 30 June 2004 Analysis by activity Upstream Shipping Total US$’000 US$’000 US$’000Turnover 58,079 4,999 63,078 Segment gross profit / (loss) 27,358 (580) 26,778 WestAnalysis by geographical area Caspian Africa Total US$’000 US$’000 US$’000Turnover 45,992 17,086 63,078 Segment gross profit 21,132 5,646 26,778 12 months ended 31 December 2004 Analysis by activity Upstream Shipping Total US$’000 US$’000 US$’000Turnover 173,778 12,009 185,787 Segment gross profit / (loss) 98,758 (837) 97,921 WestAnalysis by geographical area Caspian Africa Total US$’000 US$’000 US$’000Turnover 123,552 62,235 185,787

Segment gross profit 71,968 25,953 97,921 3. Earnings per Ordinary Share 6 months to 6 months to Year ended Earnings per ordinary share 30 June 30 June 31 December 2005 2004 2004 US$’000 US$’000 US$’000 Profit: Basic and diluted earnings per share 82,931 12,280 68,407 Number Number Number Weighted average number of shares: For basic earnings per share 138,380,457 136,175,373 136,635,254Executive Share Option Scheme 2,416,304 3,209,294 2,989,839Long Term Incentive Plan 1,337,802 1,518,485 1,459,099Performance share plan 369,546 481,922 289,100Other share options 533,053 1,212,424 1,366,626Deferred share awards 143,822 125,842 73,032

Diluted number of shares 143,180,984 142,723,340 142,812,950

Basic earnings per share (US cents) 59.9 9.0 50.1Diluted earnings per share (US cents) 57.9 8.6 47.9 4. Reconciliation of Operating Profit to Cash Flow Generated by Operations 6 months to 6 months to Year ended 30 June 30 June 31 December 2005 2004 2004 US$’000 US$’000 US$’000 Operating profit 98,116 20,185 87,186Add: Depreciation 32,036 10,614 30,182Add: Non-cash charge in respect of incentive schemes 525 1,449 5,518Less: Share of associate’s profit (483) - -Increase in inventory (269) (55) (139)Increase in trade and other receivables (22,410) (3,790) (18,309)(Decrease) increase in trade and other payables (1,908) 2,982 (800)Change in fair value of derivatives 4,644 7,560 5,061Net cash flow generated by operations 110,251 38,945 100,177

5. Taxation

6 months to

30 June 6 months to

30 June Year ended

31 December

2005

US$’000 2004

US$’000 2004

US$’000 Current tax: UK corporation tax - - 261 Foreign tax 10,274 - 1,758

10,274 - 2,019

Deferred tax: Timing differences 3,975 7,650 16,426 Attributable to a decrease in the rate of corporation tax - - (697)

3,975 7,650 15,729

14,249 7,650 17,748

6. Acquisition of Associate

On 14 February 2005, the Group acquired 100% of the issued share capital of Unocal Bharat Limited (“UBL”), a company incorporated in Bermuda, for cash consideration of US$26 million. The principal asset of UBL is a 26% interest in Hindustan Oil Exploration Company Limited (“HOEC”), a publicly quoted Indian oil and gas exploration and production company. An analysis of the Group’s 26% share of HOEC’s assets and liabilities is shown below. Book Fair value Fair value adjustments Value US$’000 US$’000 US$’000 Net assets acquired (Group share) Property, plant and equipment 3,371 23,093 26,464 Intangibles other than goodwill 2,432 - 2,432Investments 1,193 - 1,193 Deferred tax assets 546 - 546 Inventories 190 - 190 Trade and other receivables 9,387 - 9,387 Cash and cash equivalents 337 - 337 Trade and other payables (1,573) (3,407) (4,980)Loans (1,787) - (1,787)Deferred tax liabilities - (7,773) (7,773) 14,096 11,914 26,010 Consideration paid satisfied by cash 26,010 The movement in the Group’s investment in HOEC since acquisition is as follows:

US$’000At acquisition 26,010Share of profit to 30 June 2005 483Dividend receivable (399)At 30 June 2005 26,094 Hardy Oil and Gas Limited (“Hardy”), a company incorporated in the Isle of Man, has instigated legal action asserting that the acquisition of UBL by Burren infringed upon its rights, principally those of pre-emption, under a shareholder agreement signed in 1998 amongst the major shareholders of HOEC at that time. It is disputed that Hardy is party to the shareholder agreement and that the acquisition of UBL infringed upon the terms of that agreement. In the opinion of the directors, it is not probable that the outcome of these actions will result in any material adverse change to the reported financial position of the Group. 7. Trade and Other Receivables Included in this balance at 30 June 2005 is US$25 million (30 June and 31 December 2004 : US$ nil) held on deposit in a blocked account in relation to an Open Offer for an interest of up to 20% HOEC launched by the Group on 16 August 2005. The offer closed on 5 September 2005 and acceptances were negligible. Substantially all of this deposit will therefore be returned to Burren.

8. Assignment of Interest in Kouilou PSA

On 28 June 2005 Burren entered into an agreement to assign 10% of its current 35% interest in the Kouilou PSA to SNPC, the state-owned national oil company of the Republic of Congo, leaving Burren with a residual interest of 31.5%. The Kouilou PSA includes the M’Boundi field and the exploration rights to the Kouilou permit area. Cash consideration receivable by Burren is US$35 million, payable 50% in cash at completion with the balance payable out of future profit oil accruing to SNPC under the terms of the PSA.

Completion of the transaction is subject to the satisfaction of a number of conditions by the Government of the Republic of Congo, the most significant of which are (i) the granting of a new development licence for the M’Boundi field with a term of 20 years from the date of grant and an optional 5 year extension, in place of the current development licence which expires in 2017 but may be extended for a further 5 years; and (ii) the extension of the Kouakouala production licence, which currently expires in January 2008, for a further 10 years.

The effect of this transaction will be recognised in the financial statements upon completion.

9. Dividends A US$7.6 million dividend, being 3.0 pence per share, was declared during the first 6 months of 2005 in relation to the results of the year ended 31 December 2004. Since 30 June 2005 the Directors have approved the payment of an interim dividend of 2.5 pence per share, which will be paid on 28 October 2005 to shareholders on the register at the close of business on 30 September 2005. 10. Post Balance Sheet Events Since 30 June 2005 the Group has signed a new US$80 million 4 year revolving reserve-based secured loan facility, which will be available for general corporate purposes. The facility, which has been arranged by Natexis Banques Populaires and is being syndicated among a small number of European banks, has the capacity to be increased to US$150 million upon further syndication. The facility is expected to remain undrawn initially.

11. Restatement of 30 June 2004 Comparative Financial Statements under International Financial Reporting Standards (“IFRS”) The restated IFRS Group balance sheets at 1 January 2004 (the date of transition to IFRS) and at 31 December 2004 (the date of the last UK GAAP financial statements) and the restated IFRS group income statement for the 2004 financial year, together with the accounting policies adopted in relation thereto and full reconciliations to the corresponding UK GAAP figures, have already been published on the company’s website, (www.burren.co.uk).

The restated IFRS consolidated balance sheet at 30 June 2004 and the restated IFRS group income statement for the six months ended 30 June 2004 are set out below to enable a comparison of the 2005 interim figures with those published in the corresponding period of the previous financial year.

11.1 Restated Consolidated Income Statement for the six months ended 30 June 2004

Effect of transition UK GAAP* UK GAAP to IFRS IFRS NOTES £ '000 US$’000 US$’000

30,618

US$’000 Revenue a 55,823 7,255 63,078Cost of sales - Depreciation (5,821) (10,614) - (10,614)- Losses on oil price derivative contracts a - - (14,815) (14,815)- Other cost of sales (5,963) (10,871) - (10,871)Gross profit 18,834 34,338 (7,560) 26,778Charge in respect of incentive schemes b (2,411) (4,397) 909 (3,488)Other administrative expenses (1,703) (3,105) - (3,105)Total administrative expenses (4,114) (7,502) 909 (6,593) Operating profit 14,720 26,836 (6,651) 20,185Interest and investment income 152 278 - 278Finance costs (292) (533) - (533) Profit on ordinary activities before tax 14,580 26,581 (6,651) 19,930Tax on profit on ordinary activities c (4,196) (7,650) - (7,650) Profit attributable to equity holders of parent company 10,384 18,931 (6,651) 12,280

*Burren previously reported in pounds sterling but adopted US$ as its presentational currency on 1 January 2005.

Notes to the Consolidated Income Statement for the six months ended 30 June 2004

(a) Oil price derivative contracts

Under UK GAAP realised losses on oil price derivative contracts were netted off against turnover. Under IFRS, hedge accounting treatment for the outstanding contracts is not achievable owing to the absence of documentation demonstrating the effectiveness of the contract from the outset. Realised losses on these contracts, amounting to US$7,255,000, have, therefore, been included in cost of sales and revenue has been increased by an equivalent amount.

Under UK GAAP unrealised gains and losses on oil price derivative contracts relating to expected future sales of crude were only accounted for when the related physical transaction occurred. However, under IFRS, such contracts are marked to market and the fair value recognised in the

balance sheet. The resultant movement in fair values is recognised in the profit and loss account: this amounted to a loss of US$7,560,000. Together with realised losses of US$7,255,000 this resulted in a total loss on oil price derivatives contracts of US$14,815,000.

(b) Charge in respect of share incentive schemes

The Group operates a number of share incentive schemes. Under UK GAAP, deferred share awards were valued at their intrinsic value at the balance sheet date (having no regard to potential future share price movements) and charged to the income statement in the financial year to which the award related.

IFRS requires deferred share awards granted by the Group to employees to be valued at fair value at the grant date. Such fair value should be based on a model appropriate to value the inherent optionality of the incentive schemes including but not limited to potential future share price movements, and charged to the income statement pro rata over the vesting period of the related awards.

The transitional provisions of IFRS 2 allow that share incentive options granted before 7 November 2002 or which vested before 1 January 2005 are exempt from restatement. On this basis restatements have only been required for the following two schemes:

Performance Share Plan

The cost in relation to this plan, which consists of share options granted before flotation and vesting over a 3 year period, was fully charged to the income statement in the 6 months ended 30 June 2004 under UK GAAP as the related performance criteria had been met in full. Under IFRS this charge is spread over the vesting period. This has resulted in a credit to the income statement of US$959,000.

Annual Profit Share Scheme (APSS)

This scheme includes both a cash and a deferred share element, with shares issued under the latter vesting over a 3-year period. The cost of both elements of this scheme was fully charged to the income statement under UK GAAP. Under IFRS, the deferred share element of this charge is spread over the vesting period. This has resulted in a charge to the income statement of US$50,000.

This accounting change has therefore reduced the charge in respect of share incentive schemes by US$909,000.

(c) Taxation

There was no impact on current or deferred tax charges for the half year ended 30 June 2004. This was because the adjustments either increased the size of a deferred tax asset that has not been treated as recoverable or because they arose in a jurisdiction with a zero percentage tax rate.

11.2 Restated Consolidated Balance Sheet at 30 June 2004

Effect of transition UK GAAP* UK GAAP to IFRS IFRS NOTES £ '000 US$’000 US$’000 US$’000 ASSETS Non-current assets Intangible assets other than goodwill d 1,021 1,851 3,769 5,620Property, plant and equipment e - 203,535 203,535Tangible fixed assets 114,811 208,096 (208,096) - 115,832 209,946 (791) 209,155 Current assets Inventory 514 931 - 931Trade and other receivables 9,380 17,001 - 17,001Cash and cash equivalents 19,117 34,650 - 34,650 29,011 52,582 - 52,582 TOTAL ASSETS 144,843 262,528 (791) 261,737 LIABILITIES Current liabilities Trade and other payables (13,456) (24,389) - (24,389)Fair value of derivatives f - - (13,027) (13,027)Short term borrowings (366) (663) - (663) (13,822) (25,052) (13,027) (38,079) Non-current liabilities Borrowings (3,482) (6,312) - (6,312)Provisions (6,173) (11,189) - (11,189) (9,655) (17,501) - (17,501) TOTAL LIABILITIES (23,477) (42,552) (13,027) (55,580) NET ASSETS 121,366 219,975 (13,818) 206,157 EQUITY Called up share capital 25,055 45,413 - 45,413Share premium account 48,190 87,345 - 87,345Other reserves 1,708 3,096 - 3,096Merger reserve (7,016) (12,716) - (12,716)Revaluation reserve 15,329 27,783 - 27,783Shares to be issued g 2,934 5,316 (1,191) 4,125Profit and loss account h 35,166 63,738 (12,627) 51,111 TOTAL EQUITY 121,366 219,975 (13,818) 206,157

*Burren previously reported in pounds sterling but adopted US$ as its presentational currency on 1 January 2005.

Notes to the Consolidated Balance Sheet as at 30 June 2004

(d) Intangible assets other than goodwill

Under UK GAAP, intangible fixed assets represented pre-licence acquisition costs and exploration and evaluation (“E&E”) costs of individual licence interests held outside the depreciable cost pools pending determination of commerciality. Under IFRS, intangible assets have been adjusted to write off cumulative pre-licence acquisition costs of US$507,000 and to include E&E costs of US$4,276,000 that under UK GAAP had been capitalised in a full cost pool within tangible fixed assets, giving a net increase in intangible assets of US$3,769,000. Additional details are provided in the supplemental intangible assets note (note 11.4). (e) Property, plant and equipment

Under UK GAAP, tangible fixed assets comprised: • oil and gas properties for which the existence or otherwise of commercial reserves had been

established, recorded by reference to broad, geographic cost pools. This caption also included certain exploration and evaluation expenditure incurred within the cost pools.

• Other fixed assets, including non oil & gas specific plant and equipment, office furniture, barges and tugs.

Under IFRS, all amounts previously classified as tangible fixed assets have been recorded as property, plant and equipment except for exploration and evaluation expenditure of US$4,276,000 in relation to non-producing fields for which the existence of commercial reserves has not yet been determined (reclassified to intangible assets). Additional cumulative depreciation of US$285,000 has also been charged under IFRS, since costs are depreciated by reference to specific fields rather than regional cost pools. Additional details are provided in the supplemental property, plant and equipment note (note 11.4). (f) Unrealised gains & losses on oil price derivative contracts

The liability of US$13,027,000 recognised under IFRS represents the mark-to-market liability (unrealised loss) of the Brent collar contracts that were open at the period end based on market quotations.

(g) Shares to be issued

The difference between the measurement and accounting treatment of share incentive scheme awards is described in note (b) above. Under both UK GAAP and IFRS charges made to income in respect of share incentive scheme awards are credited to a "Shares to be Issued" reserve. The US$1,191,000 reduction in this reserve reflects the cumulative reduction in share incentive scheme charges to income, of which US$909,000 was credited to the 2004 half-year income statement.

(h) Profit and loss account

The above adjustments result in a US$12,627,000 reduction in retained earnings.

11.3 Restated Consolidated Cash Flow Statement for the period ended 30 June 2004

Note

UK GAAP*

£ '000 UK GAAP

US$’000

Effect of transition

to IFRS (see note i)

US$’000 IFRS

US$’000 Operating activities Cash flow generated by operations 21,367 38,945 - 38,945Taxation paid - - - -

Net cash from operating activities 21,367 38,945 - 38,945

Investing activities Purchases of intangible assets other than

goodwill

(203) (370) (1,459) (1,829)Purchases of property, plant and equipment j - - (40,842) (40,842)Purchases of tangible fixed assets j (23,202) (42,301) 42,301 -

Net cash used in investing activities (23,405) (42,671) - (42,671)

Financing activities Interest received 152 278 - 278Interest paid (223) (408) - (408)Issue of ordinary share capital 556 1,012 - 1,012Receipt from loans 197 360 - 360

Net cash provided by financing activities 682 1,242 - 1,242

Net decrease in cash and cash equivalents (1,356) (2,484) - (2,484)Cash and cash equivalents at beginning of

period

20,788 37,123 - 37,123Effect of foreign exchange rate changes (315) 11 - 11

Cash and cash equivalents at end of period 19,117 34,650 - 34,650

*Burren previously reported in pounds sterling but adopted US$ as its presentational currency on 1 January 2005. Certain captions have been reclassified in accordance with IAS 1 “Presentation of Financial Statements”.

Notes to the Consolidated Cash Flow Statement for the six months ended 30 June 2004

(i) Reclassifications from UK GAAP

The UK GAAP £ denominated figures are shown after reclassifying certain standard headings under UK GAAP (being taxation, returns on investments and servicing of finance and capital expenditure) to their equivalents under IFRS.

(j) Reclassification of fixed asset expenditure

Purchases of tangible fixed assets under UK GAAP have been reclassified to purchases of intangible assets and purchases of property, plant and equipment under IFRS.

11.4 Supplemental Non-Current Asset Notes as at 30 June 2004

Intangible assets other than goodwill

Exploration and

evaluation assets

US$’000 Total

US$’000 Net book value Under UK GAAP 1,851 1,851 Reclassifications from PP&E 4,276 4,276 W rite-off of pre-licence costs (507) (507)

Under IFRS 5,620 5,620

Property, plant and equipment

Production assets

US$’000

Exploration and

evaluation assets

US$’000 Other

US$’000 Total

US$’000 Net book value Under UK GAAP (Tangible fixed assets) 203,406 - 4,690 208,096Reclassifications to intangibles (4,276) - - (4,276)I ncrease in accumulated depreciation (285) - - (285)

Under IFRS 198,845 - 4,690 2 3,5350

Glossary

2D, 3D two (three) dimensional (in relation to seismic surveys)

bbl barrel of oil

bopd barrels of oil per day

bwpd barrels of water per day

Congo The Republic of Congo (Brazzaville)

Contractor the contracting party or parties to a PSA or PSC other than the State. There may be several contracting parties with different participating interests, one of which is designated as Operator.

EGPC Egyptian General Petroleum Corporation, Egypt’s principal state oil company

entitlement with reference to oil & gas reserves or production, that share of the working interest amount to which the Group is entitled after taking account of the State’s entitlement under terms of the relevant PSA or PSC

Gross with reference to oil & gas reserves or production, the total amount of recoverable reserves or physical production before taking account of any State or Contractor entitlements.

HOEC Hindustan Oil Exploration Company

HSEC Health, Safety, Environment and Community

PSA, PSC production sharing agreement (contract)

SNPC Société Nationale des Petroles du Congo

working interest with reference to oil & gas reserves or production, that share of the gross amount which is the same as the Group’s participating interest in the Contractor group for the PSA or PSC in question, before taking account of any State entitlement. In the case of Nebit Dag, working interest figures exclude Initial Oil to which the State is entitled in priority and which falls outside the terms of the PSA.