Alonso (left) is Renault's main man, with Piquet looking to improve in 2009
Fernando Alonso has ended months of speculation about his future by opting to stay at Renault for two more years.
The double world champion had been a Honda target but has turned them down following Renault's upturn in form.
Alonso, who scored more points than any other driver in the season's final five races, will be partnered by Brazilian Nelson Piquet Jr for a second year.
He said he stayed because Renault had "always been my first choice and I feel happy and comfortable with them."
The Spaniard rejoined Renault, with whom he won the drivers' title in 2005 and '06, at the start of 2008 after a tumultuous season as Lewis Hamiltonís team-mate at McLaren.
The team started the year poorly but they came on strong in the final third of the season after making significant improvements to the car.
That performance, in which Alonso won superbly at both Singapore and Japan, has convinced him to stay with the team in the face of Honda's courtship.
The Anglo-Japanese team have had a poor two seasons with an uncompetitive car but wanted to build their future around Alonso and were said to have effectively offered him an open chequebook.
But in a statement issued by Renault on Wednesday, Alonso said: "Renault are a very close-knit team with a competitive and winning mentality, and also a relaxed and warm attitude, which suits me perfectly.
"After a difficult start to the season, we have overcome our difficulties and constantly improved our performances.
"My back-to-back wins in Singapore and Japan, and my recent second place podium finish in Brazil, have proved how competitive we can be.
"In the past we have won championships together, as well as going through tough moments, but we are now determined to show that we can repeat that success together in the coming seasons."
Alonso had been widely linked with a move to Ferrari either in 2009 or 2010 until the Italian team decided to extend Kimi Raikkonenís contract.
But Alonso's new deal expires at the same time as Raikkonen's, making a future move to Ferrari a real possibility.
Fernando's commitment for the next two seasons confirms the faith he has in the team
Renault team boss Flavio Briatore
Renault's decision to retain Piquet is a lifeline for the son of triple world champion Nelson Piquet after a disappointing debut season.
Piquet, who was a title rival of Hamilton in the GP2 feeder series in 2006, has been well off Alonso's pace this season, although he did take a fortunate second place in the German Grand Prix in July.
There had been speculation he would be dropped in favour of another Brazilian, the teamís test driver Lucas di Grassi.
But some improved performances in the closing races of the season appear to have persuaded team boss Flavio Briatore to give him a second chance.
Piquet said: "Obviously I am delighted to have the opportunity to race for Renault for a second year.
"Although I have had a tough year, I have learned a lot from my rookie season and I will aim to put that experience to good use next season."
Briatore said the decision gave Renault "one of the most exciting driver pairings with the perfect blend of youth and experience".
He added: "Fernando's commitment for the next two seasons confirms the faith he has in the team and we are delighted to continue working with him.
"He has been a big asset throughout this difficult season and his leadership and talent, matched with the team's hard work and determination, have paid off with our recent performances."