Centrica, the owner of British Gas, raised its stake in Venture Production last night after investors controlling almost 13 per cent of the oil and gas producer rejected the utility group’s £1.3 billion takeover bid.

Centrica said that it had snapped up a further 1.3 million shares to raise its stake in Venture from 29 per cent to 29.9 per cent, only hours after Larry Kinch, a founding shareholder of Venture with a 7.4 per cent stake, and ArcLight Capital, which controls 5.4 per cent, said that they supported Venture’s rejection of the approach. They urged investors to demand more than Centrica’s 845p-a-share offer.

Mr Kinch said: “I believe Venture’s shares have a value of at least £10. In my view, other shareholders should take a longer-term view of their investment in Venture Production or at least demand a price that compensates properly for the long-term value they will give up by accepting a cash offer for the company now.”

Centrica, which on Friday said that it had bought the stake in Venture held by 3i, the private equity group, confirmed that its offer was final. It will not sweeten its bid unless a counterbidder emerges, which analysts consider unlikely now that Centrica has nearly 30 per cent of Venture, whose shares last night closed up 43½p at 828½p.

Keith Morris, of Evolution Securities, said: “Centrica’s tender offer of 845p-a-share is widely acknowledged to undervalue the company, with both management and the major shareholders Larry Kinch and ArcLight rejecting the bid.

“However, with just a further 21 per cent of acceptances required for the bid to be binding, we expect other shareholders might just decide to draw a line in the sand, accept the offer and recycle their cash. After all, the prospect of owning shares in a listed company where the management team and the major shareholder are increasingly hostile towards each other is not that appealing.”

Merrill Lynch analysts said: “The fact that 3i, which had been involved in Venture since its creation in 1997, disposed of its stake is a crucial step for Centrica and marks the limited upside that Venture, in our view, now offers.”

• Emerald Energy’s shares rose 71½p to 632p after a bid approach. Emerald, with operations in Syria and Colombia, is thought to have attracted Indian and Chinese suitors. A 750p-a-share bid would value it at £470 million.

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