MANAMA, April 3 (Reuters) - Fernando Alonso denied on Thursday that he had an escape clause in his contract with Renault that might allow him to leave for Ferrari at the end of the Formula One season.

"I don't remember that clause and I signed for two years with Renault," Spain's double world champion told reporters at the Bahrain Grand Prix.

"But as we saw last year, the contracts are always very flexible."

Pressed again on whether there was any clause allowing him to leave early, he replied: "No."

Reports from Spain last week quoted Alonso, who left McLaren at the end of last year after just one season of a multi-year contract with the Mercedes-powered team, suggesting he had an option to leave.

However the 26-year-old said on Thursday he was not giving up on Renault, the team with which he won his titles in 2005 and 2006, despite them being off the leaders' pace in the opening races.

"We are disappointed about our performance in the first two races, but it is not the time to give up at the moment, we keep working as hard as we can and then we see at the middle of the season, or the end of the season, where we are," he said.

"For next year there is a big change of rules it seems.

"Aerodynamically there will be a big change with very little wings and with slick tyres again probably. So all this can change the picture again in Formula One, so at the moment I am really convinced that we can do a good job, Renault and me together," added the Spaniard.

Renault have not won a race since Alonso's last win with them in Japan in 2006. The Spaniard finished fourth in Australia last month and eighth in Malaysia.

However he saw no reason why the team could not return to the top next year.

"When rules change dramatically it is like putting a coin in the air," he said.

"Any team can have a good car and fight for the championship.

"If the rules stay the same for the next 10 years or whatever, we know that McLaren and Ferrari will fight for the
next 10 championships. So hopefully next year everything will change a little bit and maybe we can take the benefit of it."

(Reporting by Alan Baldwin; editing by Trevor Huggins)