Slaughter and May, Linklaters and Simmons & Simmons have become the latest firms to win roles on the billion-pound bidding battle for Cove Energy.

Slaughters is advising Thailand’s PTT Exploration and Production (PTTEP), which has topped an earlier bid from Royal Dutch Shell with a new £1.2bn offer. Cove’s directors have unanimously recommended that its shareholders accept the latest bid.