Completion of farm-in

PREMIER OIL plc

("Premier" or "the Company")

Completion of the farm-in for 60 per cent of Rockhopper Exploration plc's ("Rockhopper") licence interests in the Falkland Islands

19 October 2012

Premier is pleased to announce that it has completed the farm-in for 60 per cent of Rockhopper's licence interests in the Falkland Islands, which includes the Sea Lion development. This follows the expected cash payment of $231 million by Premier to Rockhopper and satisfaction of other closing conditions (including approval by the Falkland Islands Government). Operatorship of the Sea Lion development is expected to transfer to Premier at the end of October.

Commenting on today's announcement, Simon Lockett, Chief Executive of Premier, said:

'We are delighted to complete this agreement with Rockhopper. As operator, we will progress Sea Lion to final development sanction and work closely with the Rockhopper team to mature the exciting exploration opportunities in our shared acreage.'

Enquiries

Premier Oil plc 0207 730 1111

Simon Lockett

Tony Durrant

Pelham Bell Pottinger 0207 8613232

Gavin Davis

Henry Lerwill