28.05.09

Further to the announcement released by Northern on 29 April 2009 and the posting of the Circular, the Independent Northern Directors and the Independent ATI Directors are pleased to announce that at today’s Court Meeting, the required majority of Scheme Shareholders approved the Scheme without modification. At the subsequent General Meeting also held today, Scheme Shareholders passed the proposed resolution, as set out in the notice of General Meeting dated 28 April 2009 (the “Special Resolution”).

The number of votes for and against the Scheme at the Court Meeting were as follows:

	Number of Scheme Shares voted	Scheme Shares voted as % of total Scheme Shares voting	Scheme Shares voted as % of total issued Scheme Shares	Number of Scheme Share holders voting	Scheme Share holders who voted as % of total Scheme Share holders voting	Scheme Share holders voting as % of total Scheme Share holders
For	49,169,982	100	82.85	31	100	22.63
Against	0	0	0	0	0	0

At the General Meeting, the Special Resolution was passed unanimously on a show of hands.

The Scheme and the associated Capital Reduction will also require the subsequent sanction and confirmation of the Court.

Expected Timetable of Principal Events

The following times and dates are indicative only and will depend, amongst other things, on the dates upon which the Court sanctions the Scheme and confirms the Capital Reduction and whether the Conditions are either satisfied or, if capable of waiver, waived.

Last day of dealings in ATI Shares	22 June 2009
Scheme Record Time	6:00 p.m. on 22 June 2009
Court hearing (to sanction the Scheme and confirm the Capital Reduction)	23 June 2009
Effective Date	24 June 2009
Cancellation of trading of ATI Shares	8:00 a.m. on 24 June 2009
Latest date for dispatch of New Northern Share certificates and crediting of CREST accounts under the Scheme	8 July 2009

Terms and expressions used in this announcement shall have the same meanings given to them in the announcements released by Northern on 3 April 2009 and 29 April 2009.

For further information please contact:

Northern Petroleum Plc
Tel: +44 (0) 20 7469 2900
Richard Latham, Chairman
Graham Heard, Exploration & Technical Director

Investec (NOMAD and Financial Adviser)
Tel: +44 (0) 20 7597 5000
Michael Ansell / Patrick Robb

ATI Oil Plc
Tel: +44 (0) 20 7469 2940
Per Gunnar Loge, Chief Executive Officer

KBR (Financial adviser to ATI)
Tel: +44 (0) 20 3100 8300
Hugh Oram

The directors of Northern accept responsibility for the information contained in this announcement. To the best of the knowledge and belief of the directors of Northern (having taken all reasonable care to ensure that such is the case) the information contained in this announcement is in accordance with the facts and does not omit anything likely to affect the import of such information.

This announcement will shortly be published in accordance with Rule 19.11 of the Takeover Code on Northern’s website, http://www.northpet.com, in the news section.

Dealing Disclosure Requirements

Under the provisions of Rule 8.3 of the Takeover Code, if any person is, or becomes, 'interested' (directly or indirectly) in 1% or more of any class of 'relevant securities' of the Company or ATI, all 'dealings' in any 'relevant securities' of that company (including by means of an option in respect of, or a derivative referenced to, any such 'relevant securities') must be publicly disclosed by no later than 3.30 pm (London time) on the London business day following the date of the relevant transaction. This requirement will continue until the date on which the offer becomes, or is declared, unconditional as to acceptances, lapses or is otherwise withdrawn or on which the 'offer period' otherwise ends. If two or more persons act together pursuant to an agreement or understanding, whether formal or informal, to acquire an 'interest' in 'relevant securities' of the Company or ATI, they will be deemed to be a single person for the purpose of Rule 8.3.

Under the provisions of Rule 8.1 of the Takeover Code, all 'dealings' in 'relevant securities' of the Company or ATI by the Company or ATI, or by any of their respective 'associates', must be disclosed by no later than 12.00 noon (London time) on the London business day following the date of the relevant transaction.

A disclosure table, giving details of the companies in whose 'relevant securities' 'dealings' should be disclosed, and the number of such securities in issue, can be found on the Takeover Panel's website at www.thetakeoverpanel.org.uk.

'Interests in securities' arise, in summary, when a person has long economic exposure, whether conditional or absolute, to changes in the price of securities. In particular, a person will be treated as having an 'interest' by virtue of the ownership or control of securities, or by virtue of any option in respect of, or derivative referenced to, securities.

Terms in quotation marks are defined in the Takeover Code, which can also be found on the Panel's website. If you are in any doubt as to whether or not you are required to disclose a 'dealing' under Rule 8, you should consult the Panel.

Investec Investment Banking, a division of Investec Bank plc ("Investec"), which is authorised and regulated in the United Kingdom by the FSA, is acting for Northern and for no-one else in connection with the Proposals and the matters referred to in this announcement and will not be responsible to anyone other than Northern for providing the protections afforded to customers of Investec or for providing advice in connection with the matters set out in this announcement.