Mark Webber celebrated turning 35 on Saturday by signing a one year extension to his Red Bull contract for the 2012 season.
The Australian, who topped the times in Friday practice for Sunday's Belgian Grand Prix, said: "I want to continue racing at the top in Formula One so it's a no brainer to remain at Red Bull Racing for another year.
"My motivation to achieve the best results possible both for myself and the team is still very high.
"Over the past five years, we have worked hard and proved that we can design and build a competitive and championship-winning car, and I'm looking forward to putting the car and myself on the limit again each and every race weekend in 2012."
Red Bull boss Christian Horner said agreeing Webber's new deal had been "very straightforward".
"When we sat down and started talking about 2012, it was immediately obvious that Mark and the team wanted to continue our successful relationship.
"Mark knows the team well, having been with us since 2007, and his motivation, fitness and commitment is as high as it has ever been.
"The pairing of Mark Webber and Sebastian Vettel is a very strong one, they push each other hard and we are extremely happy the pairing will remain unchanged for a fourth season."
Webber has experienced a sometimes strained relationship with his team-mate and world champion Sebastian Vettel at times in recent years, but has proved to be a strong and brave racing driver.
The only one of the leading drivers still without a win this year, Webber is lying second in the driver's standings on 149 points behind Vettel on 234.