Four times world champion Sebastian Vettel is leaving Red Bull at the end of the season and is set to join Ferrari, the Formula One team said on Saturday.

Red Bull said in a statement Vettel’s seat would be taken by 20-year-old Russian driver Daniil Kvyat, while team boss Christian Horner said at the Japanese Grand Prix on Saturday the German would be racing for Ferrari from next season.

Vettel’s departure may trigger a merry-go-round of team switches, with Fernando Alonso’s future at Ferrari a hot topic of paddock discussion.

Alonso’s contract runs until the end of the 2016 season but the 33-year-old Spaniard has been linked heavily with a move to former outfit McLaren.

“Sebastian Vettel has advised us that he will be leaving Red Bull at the end of the 2014 season," Red Bull said in a statement. “We want to warmly thank Sebastian for the incredible role he has played at Red Bull for the last six years.

“As we wish Sebastian well in the next stage of his career, we also look to the future with excitement, as the vacancy makes way for the next generation of Red Bull racers," the team added.

Red Bull boss Horner told Sky Sports that Vettel informed him of his decision on Friday.

“He informed us last night and obviously had his reasoning behind that. I don’t think he’d taken the decision lightly and was obviously very emotional about it," he said.

“But if it’s his desire to be somewhere else, then it’s not right for us to stand in his path.

“As of January 1st he’ll be a competitor. He’ll be a Ferrari driver."

Ferrari had not made any announcement on Saturday about their future line-up.

Vettel frustrations

Vettel has struggled to recapture championship form this year following the implementation of new technical regulations for the sport, and has yet to win a race.

He is fifth in the championship standings, with team mate Daniel Ricciardo third behind the Mercedes pair of Lewis Hamilton and Nico Rosberg.

Vettel’s frustrating season continued on Saturday when engine problems forced him out of final free practice at Suzuka.

Vettel’s replacement, Russian Kvyat, became the sport’s youngest ever points scorer at the age of 19 in Melbourne in March. He has scored eight points this season and is 15th in the drivers standings.

“I was very honoured, very surprised," the BBC quoted the Toro Rosso driver as saying at Suzuka. “The people around me know I like to work hard and do my best."

Speculation surrounding Alonso’s future has been rife this year, a season that has seen a number of key management changes at Ferrari, with long-serving president Luca di Montezemolo the latest to announce his departure.

The Spaniard, currently driving in his fifth season with Ferrari, has grown increasingly disillusioned with the lack of success for the sport’s glamour team which has not won a race in over a year and faces the prospect of recording their first winless season since 1993. Reuters