* Massa leaving Ferrari at end of season
* Raikkonen favourite to return to his former team (Recasts with Massa leaving)
By Alan Baldwin
LONDON, Sept 10 (Reuters) - Brazilian Felipe Massa announced on Tuesday he was leaving Ferrari at the end of the season, opening the door for Kimi Raikkonen to return to the Formula One team that took him to the title in 2007.
"From 2014 I will no longer be driving for Ferrari," the driver said in a post on Instagram and Twitter. "I would like to thank the team for all the victories and incredible moments experienced together.
"For next year, I want to find a team that can give me a competitive car to win many more races and challenge for the Championship...," he added.
Raikkonen, who currently races for Lotus, has been widely tipped to return to the team he left in 2009 to make way for Spain's double champion Fernando Alonso.
There was no word from the team, however, with Ferrari chairman Luca di Montezemolo earlier avoiding questions about the Finn when questioned by reporters at the Frankfurt motor show.
"We won't talk about Formula One today," the Italian said. "I am trying to convince a driver to come back and am speaking to Schumacher tomorrow," he joked.
Seven-times champion Michael Schumacher, now 44 and fully retired after his comeback with Mercedes ended last year, is most definitely not in the running. Raikkonen, the 33-year-old with the glacial gaze and 'Iceman' tattooed on his forearm, certainly is.
Paddock whispers after last weekend's Italian Grand Prix at Monza spoke of a done deal, although Lotus also said they were still hoping to keep their man and Germany's Nico Hulkenberg has also been considered to be in the frame.
Raikkonen has plenty of supporters among the passionate Ferrari 'tifosi' as the team's first champion of the post-Schumacher era, and last to date, and his return would be a break with Ferrari tradition as much as a blast from the past.
If he is named as Massa's replacement, and unless Alonso also drops a bombshell, Ferrari will have a former world number one on both sides of the garage next season for the first time since most fans can remember.
In the 1950s, team founder Enzo Ferrari had Italian champions Alberto Ascari and Giuseppe Farina racing in his cars together but Montezemolo has spoken out in the past against having "two roosters in the same henhouse".
Alain Prost and Nigel Mansell were there together in 1990 but the Briton would have to wait until 1992 with Williams before he became a champion.
Since the arrival of Michael Schumacher in 1996, Ferrari has preferred to be a team with one driver clearly ranked ahead of the other.
While speculation about Massa's future has been a regular occurrence of recent seasons, this time the Brazilian recognised he had run out of road and his exit could leave his country without any driver on the starting grid.
Massa has not won since 2008, when he was overall runner-up, and has been on the podium just once this year. But he was a loyal team mate to Alonso who made clear who he would rather have in the other red car.
"I have a lot of respect for Felipe. We've been working very hard and close for four years to give Ferrari the maximum," Alonso said in a response to fans on Twitter on Monday.
"Whatever decision the team will take will be good for me and we will keep working to give Ferrari the best results possible."
Raikkonen is a man who refuses to be anything other than himself, an often taciturn soul who would happily skip most media engagements and likes to let his driving do the talking. Not much fazes him, least of all paddock mind games.
When the Finn left Ferrari in 2009 to make way for Fernando Alonso, he went without burning any bridges. When he came back, after two years in rallying, it was like he had never been away.
A Ferrari vacancy, the seat every aspiring racing driver dreams of, is a rare occurrence - leaving aside the occasional stand-in role - and headline news in Italy.
"We are putting on the table all the elements," Ferrari team principal Stefano Domenicali told reporters after the race at Monza on Sunday, adding that the decision was not an easy one to take. (Additional reporting by Jennifer Clark in Frankfurt, editing by Pritha Sarkar)