On Sunday evening at Valencia, Valentino Rossi and Honda formally announced that their relationship is over, confirming the biggest shake-up seen in the sport since Mick Doohan's injury induced retirement, in 1999.

After a partnership spanning four seasons, which has yielded three world titles and 33 premier-class victories, the Japanese factory and the reigning World Champion confirmed their separation to a packed press conference just hours after the Italian's final victory on the RC211V at Valencia.

Rossi revealed that he felt he had achieved everything he possibly could on the V5 machine and added that he was looking forward to racing against it next season.

"I have to say thank you very much to Honda. It is true. Next year we don't race together," he began. "For sure it has been a fantastic period for me to work together for four years. It's been unforgettable. We've won 50% of the races when we have been together. The story is only four years but for me it seems much longer.

"Together we start in 2000 with a new challenge with the 500. There were many problems to start with. Straightaway we were working with HRC and it as amazing. To work with HRC for a rider is like a dream. If you are able to give the right information to the engineers they are able to change.

"At the end of the first year we arrive in second position in the championship and take more podiums than anyone else.

"The next year I have a new NSR - after six or seven years of the old NSR. We win 11 races and the championship. It was a great championship as it was the last of the 500's. The 500cc was the story of the sport. To win the last 500cc race was like a dream. Maybe one of the best races of my career.

"After, we sign a new contract and we start another time from zero with the new 4-stroke. I first ride at Suzuka in 2001 in August. It was already a good bike. But even at the beginning I was wondering if it was as good as the 500's as it was not as fast. We work hard and the bike was ready for the first GP and we win. At the end of last season the Yamaha was at the same level and we make a good step over the winter in testing and arrive this season in good shape.

"This year was great for me. We make many emotional races. We had a good second part of the championship. At a point after Sepang the idea arrived about making a change because we win in the dry, we win in the wet, we win at circuits I like and like today, we win at circuits I have not had such good luck at in the past. We finish our work with the bike.

"My work on (the RCV) is now finished. I am a HRC rider until the 31st December so I cannot comment yet on which bike I will be riding, but I can say that it will be a big challenge - it maybe even seems a little crazy right now!" was all Vale would say of his future - almost certain to be with Yamaha. "I think all the journalists, fans and everybody involved in this sport is very happy because next year will be a great fight.

"I have just one more small request, would Honda please let me test the new 2004 machine before I leave!" he joked.

HRC sporting manager Carlo Fiorani (pictured with Rossi) admitted that Honda had tried everything to keep Rossi, but that ultimately they were unable to offer the new challenge he seeks.

"Everyone in this room knows; indeed anyone with even the slightest interest in motorcycle racing around the world will know that we at Honda have been in contract negotiations with Valentino Rossi's management for much of this season," stated Fiorani.

"We at Honda have done everything in our power to secure Valentino's services for next year. In the end we understand that it is not about money, sponsor obligations or any of the standard issues that are negotiated over in more general contract discussions. The area we have had difficulty in, is one of providing Valentino with a new challenge and it is an area we at Honda totally understand. This is totally a Valentino choice.

"Throughout his career Valentino has moved onto a new challenge every season and in the end, it is this that Valentino seeks. In many ways his driving force is reflected in the spirit of this great company. Soichiro Honda who founded the business over 50 years ago understood and rejoiced in this spirit.

"So, on the evening of the final Grand Prix of 2003, and Valentino's 64th with Honda, we announce officially today that Honda and Valentino Rossi will not be renewing any contract for the 2004 season.

"We are obviously very sad on the one hand to see Valentino go but feel that we as a manufacturer and Valentino as a rider part company as friends with the best memories of our time together. We now have to look forward to next season when we will gather a team of riders capable of retaining the World Championship for Honda.

"I'd like to publicly thank Valentino for all the success and fun we've had over the last four years. The Honda / Rossi partnership has been an incredible one. Together we have won three World Championships, three Manufacturers Titles and 33 races in four very special years.

"We have had this situation before when riders either move teams or retire. Mike Hailwood, Freddie Spencer, Wayne Gardner, Eddie Lawson, Mick Doohan and now Valentino Rossi.

"On behalf of all at Honda, the racing community and fans world-wide I thank you for your efforts Valentino and I wish you well in the future and we look forward to the challenge of 2004 and beyond," concluded the Italian.

Yamaha, who are belived to have secured Rossi's services for 2004, insist that he is still to sign with them (see seperate story).

However, that now seems a mere formality (although there is still one seat still spare at Ducati) and Valentino will surely now set his sights on claiming Yamaha's first premier-class world championship since Wayne Rainey in 1992.