The oil and gas sector was set alight today after Centrica parked its tanks on the North Sea gas platforms of Venture Production, and unloved African explorer BowLeven received a takeover offer valuing it at more than treble its London-quoted price.

Centrica, the British Gas group, said it has spent £240 million buying a 22% stake in Venture at 725p a share, a 25% premium to the closing price last night. Centrica is looking at buying more shares, and signalled it could make an outright takeover offer in cash for the company at a total cost of more than £1 billion.

Venture said any offer at 725p “grossly undervalues” the company. Centrica has made no secret of its need to acquire upstream assets to supply gas to its 10 million residential and 400,000 business customers in the UK.

Venture is a classic North Sea “vulture” play, having picked up and developed gas fields left by the industry majors because they were too small or too difficult. It doubled profits to £230 million last year, when it produced the equivalent of an average of 45,000 barrels of oil a day.

The move on Venture is Centrica's biggest in the North Sea after a string of smaller deals. The company has plenty of cash following a £2.2 billion rights issue that was originally earmarked for its stalled part-acquisition of British Energy.

The 1431/2p rise in Venture's shares to 7231/2p was, however, eclipsed by the surge in shares of BowLeven, a sometimes controversial explorer operating in Cameroon and Gabon.

BowLeven, which makes no money, and has no production and no booked reserves but about $40 million (£28.7 billion) of cash, said it had received an offer from an unnamed suitor valuing its shares at 150p. The shares rose 64p to 105p.