Red Bull Racing team principal, Christian Horner has said Sebastian Vettel's decision to extend his deal with the Milton Keynes-based outfit was 'more a formality than anything else'.

News of the new agreement, which will see the 25-year-old stay with Red Bull until at least the end of 2015, was confirmed earlier this week [see separate story - HERE].

"It was more of a formality than anything else," Horner confirmed to Sporting Life. "We have a long-term agreement with Sebastian, and it was just perfect timing for both sides to extend for another year."

While the new deal sees the German commit only for one more year - his old deal ran until the end of 2014 - Horner insisted it still shows his loyalty to the team.

"The details of the contract between the parties are always going to be confidential," he continued. "The fact he has signed this extension though shows his commitment to Red Bull, and hopefully the relationship will go beyond 2015, which is already some way into the future.

"He's been part of the Red Bull family, since starting out as a junior, for more than 12 years now, so he's grown up with Red Bull.

"He's achieved all 29 victories in cars designed by Adrian [Newey - our chief technical officer], and he is still growing and developing as a driver.

"He enjoys the environment he is working in, we enjoy having him and working with him. It's a relationship that works."