MADRID, April 21, 2008 (AFP) - Two-time world champion Fernando Alonso, who has hinted he may quit Renault at the end of the season, promised on Monday to stay with the French team as long as they have a "winning" car.

"My first option is to stay at Renault if we succeed in creating a winning car, and the truth is we are making progress," the Spaniard told the newspaper El Pais.

"But what I want is to race in a car that can give me victories. There are several, Williams, Toyota, BMW and Ferrari that are always on top no matter what happens," he added.

After a disappointing start to the season, Renault has been experimenting with changes to its R28 car, aimed at improving its aerodynamic setup.

"I hope that our work will pay off and that our car will allow us to move up the classification," he said in comments released by Renault on Monday.

"It will not be easy. Qualifying will again be essential. We must get a good grid place and then try to pick up as many points as possible."

Renault´s technical director Rob Bell said the team was confident the car will improve following successful testing sessions at the Montmelo circuit near Barcelona, where the fourth Grand Prix of the season is to take place on April 27.

Alonso, who won back-to-back world championships with Renault in 2005 and 2006 and came close last year with McLaren, has hinted at leaving the French team if it does not perform well this season.

He presently lies in ninth place in the drivers´ standings, while Renault is sixth in the constructors´ race.

The 26-year-old also claimed he had no problems with British teammate Lewis Hamilton during their contentious time together at McLaren.

"There is always a lot of talk about him and this antagonism was created but there was never any problem," he told El Pais.

Alonso has rejoined Renault after spending a season with McLaren that was marked by media speculation of a feud between the two drivers, and accusations that the team favoured Hamilton.

Hamilton controversially won the 2007 Hungarian Grand Prix after Alonso was dropped from pole for holding up his team-mate during qualifying.

The world champion was demoted five grid places after a stewards´ investigation ruled Alonso had been wrong to wait in front of Hamilton in the pits for 30 seconds ahead of the pair´s final qualifying runs.

"People talk about Hungary, of the pit-stop, but it was not his fault," Alonso told El Pais.

"It was the team that should have taken steps and if I was supposed to leave first and make an extra round to burn more gas they should have made sure that things would be that way. But they weren´t interested in all that," he added.