UPDATE 2-Alitalia investors consider possible sale -sources
* Some investors favour sale to Air France-sources
* Lock-up period for trading shares ends Jan. 12
* Air France, IMMSI investor say no talks going on (Adds comments by IMMSI, source and banker)
MILAN/ROME, Jan 7 (Reuters) - Investors in Alitalia who helped rescue the airline four years ago are considering selling their shares, with some pushing for a deal with long-time stakeholder Air France-KLM, sources with knowledge of the situation said on Monday.
Shares in Italian holding company IMMSI, which owns 7 percent of Alitalia, closed up 18 percent at 0.53 euros following speculation of a possible sale to Air France-KLM.
But the Franco-Dutch group which owns a quarter of Italy's flagship airline said there were no talks going on.
"There is nothing. There are no negotiations," Air France's chief executive Alexandre de Juniac told Reuters. He also said that the airline's resources for such a move were extremely limited.
In a statement later on Monday IMMSI also denied there were any talks under way to sell its 7.08 percent stake in A litalia.
On Sunday Italian newspaper Il Messaggero had said that Air France was in advanced talks to buy the whole of Alitalia, offering a 20 percent premium to what the CAI consortium of domestic investors had paid when the airline was rescued in 2008.
CAI is made up of listed and unlisted Italian companies and amongst the biggest shareholders are Intesa Sanpaolo, with 8.9 percent, road operator Atlantia with 8.9 percent and IMMSI, which also controls scooter-maker Piaggio.
CAI paid just over 1 billion euros ($1.30 billion) to rescue the airline, weighed down by debt after years of mismanagement, political interference and labour unrest.
The investors in the CAI consortium can exercise options to trade their shares when a lock-up period ends on Jan. 12.
A source close to one of the investors said that any sale of shares before October required the go- a head from the Alitalia board and that the other shareholders had a right of first refusal.
Two other sources close to Italian shareholders said there were no formal talks to sell Alitalia, now valued by some analysts at just over 1.1 billion euros. But they also said investors were starting to weigh options ahead of the Jan. 12 lock-up expiry.
"Discussions with the advisors have not yet begun. Investors are starting to think about what to do ahead of Jan. 12," said a source close to one of the investors.
"Alitalia had from the start been talking about the opportunity to look for an industrial partner. Air France is already an investor and if all the pieces fall into place, it (a sale to Air France) would be the easiest option."
Italian investors have already approached several banking advisors to help find a buyer.
"It's obvious that there is some movement among investors. The impression is that (Alitalia's chairman Roberto) Colaninno is pushing for a deal with Air France but not all the shareholders agree," another source close to the situation told Reuters.
Colaninno, who also controls IMMSI, is the head of the CAI consortium.
"Those who took a stake in the rescue deal are not active in the airline sector. They could sell, but they want to make some money," said the first source close to one of the shareholders. "However, the situation is delicate as the elections near," the source added.
Mediobanca analyst Massimo Vecchio said in a research note that the only hurdle for a deal was political.
Air France tried to take over the Rome-based airline just over four years ago. But the deal was scuppered by then Prime Minister Silvio Berlusconi, who asked the Italian investors to rescue the carrier instead.
Centre-right leader Berlusconi, who is running again for prime minister in a February election, said at the weekend he was still against the airline's sale to a foreign buyer.
"I suspect that these guys (the Italian investors) are now passing on the message they would be happy to exit sooner rather than later," a banker familiar with the situation said.
But a transport sector banker said Air France already benefitted from synergies through its Skyteam alliance with the Italian carrier.
"A deeper integration would only be more troublesome at a time when both companies need to restructure and cut back," he said.
Alitalia returned to profit in the third quarter after reporting losses in the first half, booking a net profit of 27 million euros ($35.2 million), down from 70 million euros a year before. Net debt rose to 923 million euros at the end of September, up by 61 million euros from the end of June. ($1 = 0.7666 euros) (Additional reporting by Lisa Jucca, Massimo Gaia, Andrea Mandala, Stephen Jewkes and Danilo Masoni in Milan, Massimiliano Di Giorgio and Stefano Bernabei in Rome, Tim Hepher, Blandine Henault and Cyril Altmeyer in Paris, Sophie Sassard in London; Writing by Lisa Jucca; Editing by Jane Merriman and Greg Mahlich)