Drilling Update - Catcher Drill Stem Test

PREMIER OIL PLC

("Premier")

Drilling update - Catcher drill stem test

15 June 2010

Premier Oil plc notes that the operator of the Catcher well has today announced that the testing operations on the oil discovery located in the UK Central North Sea Block 28/9 have been completed and the well will now be sidetracked approximately 0.5 kilometres to the east.

The successful well test and fluid sampling programme confirmed 30 degree API gravity oil in the high quality Cromarty reservoir. Oil flowed naturally to surface but no meaningful flow rate could be measured due to mechanical issues most likely due to sand control. The well test revealed a productivity index which reflects excellent average reservoir permeability. Excluding the mechanical issues, the well would have likely flowed at a rate in excess of 7,500 bbl/d. The co-venturers have decided that the information gathered to date is sufficient for development studies to be undertaken.

The sidetrack will target a segment to the east of the Catcher discovery, within the Tay formation.

Premier's recoverable reserves range estimate of 25-50 mmbo for Catcher is unchanged.

Enquiries

Premier Oil plc Tel: 020 7730 1111

Simon Lockett

Tony Durrant

Pelham PR Tel: 020 7337 1500

James Henderson

Gavin Davis

Evgeniy Chuikov

Notes to editors:

Premier is a leading FTSE 250 independent exploration and production company with oil and gas interests in the North Sea, Asia and in the Middle East-Pakistan regions. Our strategy is to add significant value for shareholders through exploration and appraisal success, astute commercial deals and optimal asset management.