Premier Oil has renegotiated the terms of its $625 million deal to acquire UK North Sea assets from BP, achieving a “big win” of cutting the decommissioning liabilities associated with the assets by $360 million.

Under the new terms agreed for BP’s operating interest in the Andrew Area and non-operating interest in the Shell-controlled Shearwater assets, Premier will pay $210 million in cash on completion of the deal, which was originally announced in January when oil prices were at about $60 per barrel of Brent.