GDF Suez, the French power giant, is considering a revamped bid for International Power (IP), a £5bn independent power generator.
Talks collapsed last month after GDF offered to transfer assets into IP in return for a majority stake. But IP, led by chief executive Philip Cox, believed that the bid undervalued the British company, which has stakes in more than 45 power stations around the world.
A source close to GDF said that it is thinking of returning with a sweetened offer, likely to include cash for shareholders. "The situation is being actively monitored and all options are being pursued, including a cash element," he said.
A market source close to IP said that shareholders might be "cajoled" into accepting an offer should they be offered some cash, but added that it would have to be "full and fair" and would have to include a premium on the company's current market value, which is just shy of £5bn.
There was speculation this week that GDF had decided against a bid, instead turning its attentions tobuilding a stake in Suez Environnement, which supplies drinking water to 76 million people worldwide.
However, a GDF source claimed that doing one of the deals did not necessarily preclude the pursuit of the other. Advisers Goldman Sachs, Rothschild and BNP Paribas are understood to still be calculating how best to structure the IP offer.
The deal remains important to GDF as it would help it expand into the UK, where it has limited operations, but is bound to raise security concerns over so much of the UK's energy supplies being foreign owned. The move would also mean that GDF kept pace with domestic rival EdF, which last year bought a stake in nuclear generation group British Energy for £12.5bn.
The move would also buttress GDF's position as the world's biggest independent power producer; it has annual sales of €83bn (£73bn), 200,000 employees and listings on the Brussels, Luxembourg and Paris stock exchanges.
Mr Cox was reported to have spoken directly to his GDF counterpart, Gérard Mestrallet, before Christmas. IP was believed to have brought in investment bank Nomura to work on defence tactics.
As well as European locations like Italy, Portugal and Spain, IP has operations in distant territories including Pakistan, Australia and Indonesia. The company announced last month that it had completed finance for a 110mW gas-fired plant in Thailand.
In its last full year results to 31 December 2008, IP's pre-tax profit was £915m, nearly double the previous 12 months. Its shares closed at 313.9p on Friday, down 3p from the start of the day's trading. A GDF spokesman declined to comment.