Joint Venture with Antrim

PREMIER OIL plc

("Premier" or "the Company")

Joint Venture with Antrim

7th October 2010

Premier Oil plc ("Premier") is pleased to announce that it has signed an agreement with Antrim Energy Inc ("Antrim") jointly to study options for the Fyne Area in the UK Central North Sea. Under the terms of the agreement, Premier will have the option to acquire a 39.9% interest in Block 21/28a containing the Fyne field in return for payment of up to US$50 million towards the pre-development and development costs of the Fyne field which includes an immediate US$2 million payment and may include the drilling of an appraisal well on the Eastern part of the Fyne structure.

Antrim owns a 75% working interest in Block 21/28a, and a 100% working interest in the adjacent Blocks 21/28b, 21/29c, 21/24b and 21/24c (the Greater Fyne Area). The agreement also provides Premier with the option to participate at a working interest of up to 50% alongside Antrim in a planned drilling programme scheduled to start as early as the second quarter of 2011 in the Greater Fyne Area.

Block 21/28a was assigned proved plus probable reserves of 23.3 million barrels of oil by independent engineering consultants McDaniel & Associates Consultants Ltd. in their 31 December 2009 reserve report.

Any licence assignment under this agreement will be subject to the usual UK government approvals.

Simon Lockett, Chief Executive Officer, commented:

"We are pleased to have reached agreement with Antrim to be able to exploit the existing discovered reserves and to pursue additional opportunities in the Greater Fyne area of the UK Central North Sea. This is in line with our stated strategy of utilising our financial and operating strengths to build our portfolio in our core areas of activity."

Enquiries

Premier Oil plc 020 7730 1111

Simon Lockett

Tony Durrant

Pelham Bell Pottinger

Gavin Davis 07910 104 660