Juan Pablo Montoya has decided to turn his back on Formula One at the end of the season and will make a switch to NASCAR next year, autosport.com can reveal.The McLaren driver's future has been the subject of intense speculation for months, as it appeared his options to remain in Grand Prix racing were narrowing.But Montoya has now inked a deal with Chip Ganassi Racing to compete in Nextel Cup as of next year - and autosport.com understands that it is a long term one.Montoya enjoyed a successful relationship with Ganassi when he captured the 1999 CART championship and the 2000 Indianapolis 500 crown. Recently Ganassi said he would be interested in recruiting the Colombian, but it had been thought that this was for his Indy Racing League outfit.However, sources close to Montoya have revealed that talks between the driver and his former team boss have focused on a move to NASCAR, with Chip Ganassi Racing having been looking for a replacement for Casey Mears.Those talks have culminated this weekend in a deal being signed, with Montoya taking over the No. 42 car from the start of next season. Although Montoya has never raced a NASCAR, he did spend some time behind the wheel of Jeff Gordon's Monte Carlo during a promotional activity at Indianapolis in June 2003.Sources close to Montoya have indicated that Montoya became excited by the option of NASCAR when it was presented to him last month. "He's just glad to be going back home," said one source.Montoya said recently that he was far from concerned about his future in motor racing - and admitted that 'anything was possible' in terms of where he would be racing."Well I am quite relaxed," said Montoya when asked about his feelings on getting a deal for next year. "I am looking at my options and we will see what happens. I am not too worried about anything. Nothing is sure but I am pretty happy."When asked if he was confident he would remain in F1, Montoya said: "I don't know. I am looking at all my options and we will see what happens."I am not too worried about it. I am trying to put myself in the best position of where I am going to be happiest."Ganassi was unavailable for comment about the deal, but speaking recently he said that his target for Mears' replacement would be in simply signing the fastest guy possible."You have to take the best guy that is available to you, whoever he is, wherever he is, whatever he is," he said. "There are a lot of teams looking for drivers."Am I happy about this? No. Am I happy to be in this situation? No. Is it a disaster? No, it's not a disaster, either. It's just part of the business."Single seater drivers have had mixed success in making the switch to NASCAR. Former Champ Car champion Jimmy Vasser competed in a few Busch Series races before calling it quits, as did Paul Tracy who subsequently signed a five-year contract extension to remain in single seaters. Michel Jourdain Jr. left Champ Car for NASCAR but failed to make an impact in Busch or the Truck Series.The one exception to the rule is former IRL champion Tony Stewart, who has two Nextel Cup championships to his name and shares the same kind of aggression on the track that is a hallmark of Montoya.Only last weekend, former world champion Jacques Villeneuve said that he would consider a switch to NASCAR once his F1 career was over."Going to NASCAR might not be such a bad career move because it's the most exciting race series in the U.S. and it's a very different discipline to F1," he told the Red Bulletin. "I would not consider it a step down. Would I consider a move to stock cars? I would."