Public Opening Position Disclosure

(a) Identity of the party to the offer making the disclosure:

Premier Oil plc

(b) Owner or controller of interests and short positions disclosed, if different from 1(a):The naming of nominee or vehicle companies is insufficient

(c) Name of offeror/offeree in relation to whose relevant securities this form relates:Use a separate form for each party to the offer

Premier Oil plc ("Premier")

(d) Is the party to the offer making the disclosure the offeror or the offeree?

Offeror

(e) Date position held:

4 October 2011

(f) Has the party previously disclosed, or is it today disclosing, under the Code in respect of any other party to this offer?

Yes - EnCore Oil plc

Class of relevant security:

Ordinary Shares of 12.5p each

Interests

Short positions

Number

%

Number

%

(1) Relevant securities owned and/or controlled:

Nil

-

Nil

-

(2) Derivatives (other than options):

Nil

-

Nil

-

(3) Options and agreements to purchase/sell:

Nil

-

Nil

-

TOTAL:

Nil

-

Nil

-

Class of relevant security in relation to which subscription right exists:

None

Details, including nature of the rights concerned and relevant percentages:

None

Details of any irrevocable commitments or letters of intent procured by the party to the offer making the disclosure or any person acting in concert with it (see Note 3 on Rule 2.11 of the Code):

Details of any interests, short positions and rights to subscribe of any person acting in concert with the party to the offer making the disclosure:

It has not been practicable for Premier to make enquiries of all of its concert parties in advance of releasing this Opening Position Disclosure and therefore this Opening Position Disclosure does not include all relevant details in respect of Premier's concert parties. Details of the Premier directors' interests are set out below.

Premier confirms that a further disclosure in accordance with Rule 8.1(a) and Note 2(a)(i) on Rule 8 of the Code will be made as soon as possible, if required.

Name

Number ofexisting Premier shares

Percentage of Premierissued share capital

Robin Allan

422,680

0.090%

Joe Darby

23,108

0.005%

Tony Durrant

1,050,071

0.224%

Neil Hawkings

611,151

0.131%

Jane Hinkley

4,000

0.001%

David Lindsell

17,332

0.004%

Simon Lockett

1,281,463

0.274%

Andrew Lodge

231,484

0.049%

Mike Welton

22,531

0.005%

Total

3,663,820

0.783%

The following Premier directors have the right to acquire Premier shares pursuant to the Premier SAYE option scheme.

Name

Number of shares subject to option

Exercise price

Lapse date

Robin Allan

8,048

£2.0344

30/11/2012

Simon Lockett

3,480

£2.605

30/11/2013

Andrew Lodge

3,480

£2.065

31/12/2013

Details of any indemnity or option arrangement, or any agreement or understanding, formal or informal, relating to relevant securities which may be an inducement to deal or refrain from dealing entered into by the party to the offer making the disclosure or any person acting in concert with it:

If there are no such agreements, arrangements or understandings, state "none"

None

Details of any agreement, arrangement or understanding, formal or informal, between the party to the offer making the disclosure, or any person acting in concert with it, and any other person relating to:

(i) the voting rights of any relevant securities under any option; or

(ii) the voting rights or future acquisition or disposal of any relevant securities to which any derivative is referenced:

If there are no such agreements, arrangements or understandings, state "none"

None

Supplemental Form 8 (Open Position)

No

Supplemental Form 8 (SBL)

No

Date of disclosure:

5 October 2011

Contact name:

Andy Gibb

Telephone number:

+44 (0)20 7730 1111