Jorge Lorenzo has explained that loyalty and competitive machinery were the reasons he signed a new Yamaha MotoGP contract, but thanked Ducati for making it a difficult decision.

The 22-year-old Spaniard has been a MotoGP frontrunner ever since qualifying on pole for his premier-class debut at the start of the 2008 season.

During his 28 MotoGP races, all with Fiat Yamaha, Lorenzo has taken three wins and 14 podiums - handing him the 2008 rookie of the year title and second in the 2009 standings, behind team-mate Valentino Rossi, after eleven of 17 rounds.

Lorenzo's new one-year Yamaha deal brought to an end months of speculation, which began with rumours of a Honda switch, before a late big-money offer from Ducati.

"Firstly, I have to thank Ducati for their interest because the offer they made was difficult to reject," Lorenzo told Spanish sportspaper AS. "In the end, I decided to remain with Yamaha because of the confidence they placed in me three years ago, before I had even won a 250cc title. I remain with Yamaha because of this and also because I have two years experience with the motorcycle. I know it very well and I think that is the best option to try to win the title."

Although unwilling to discuss his new Yamaha pay deal, rumoured to have been doubled from 2 to 4 million euros a year, Lorenzo admitted that "if I was only interested in money, I would have gone to Ducati."

Ducati is said to have offered Lorenzo 6.5 million euros a year (second only to six time MotoGP champion Rossi, on 14 million a year).

While Yamaha resisted becoming involved in a financial bidding war for Lorenzo, there does seem to have been some concessions from the Japanese factory to help clinch the deal.

"I have to thank Lin Jarvis, and also Furusawa, because they promised me that I would have the same motorcycle as Valentino for the second half of this year and all of next year," he revealed. "That was a very important point in making my decision."

Earlier in the season, Lorenzo told that his M1 was 'almost the same' as Rossi's.

Lorenzo's deal means that he joins Rossi (Fiat Yamaha), Casey Stoner (Ducati Marlboro), Marco Melandri (Gresini Honda), Marco Simoncelli (Gresini Honda), Alvaro Bautista (Rizla Suzuki) and Hector Barbera (Aspar Ducati) in having a confirmed place on the 2010 grid.