Discovery at Erne, UK North Sea

PREMIER OIL PLC

("Premier")

Discovery at Erne, UK North Sea

1 December 2011

As announced by Antrim Energy Inc., Premier is pleased to note the preliminary results of the Erne exploration well, 21/29d-11, in the UK Central North Sea. (Premier 50 per cent working interest.)

The Erne well has been drilled to a total depth of 5,562 feet. A gross hydrocarbon column in excess of 50 feet was encountered in the Eocene Upper Tay Sandstone, according to preliminary estimates. This includes 20 feet of net oil pay and ten feet of net gas pay, with average porosity exceeding 30 per cent and average hydrocarbon saturation of approximately 80 per cent. A sidetrack well from the pilot hole will now be drilled to further delineate the reservoir.

Erne is situated between the Premier-operated Fyne field and the West and Northwest Guillemot fields.