Rumours that V8 Supercars Australia prevented former Champion Marcos Ambrose from competing at the Sydney Telstra 500 are wide of the mark according to series boss Tony Cochrane.

Speaking at the BigPond 300 in Perth, Cochrane revealed that the rules of the sport and its teams meant Ambrose - now competing in the NASCAR Sprint Cup - could not appear on track, as much as it would have been a bonus for the event and V8 Supercar fans.

"We would have loved Marcos to race but it simply couldn't be done," Cochrane said. "Under our team rules and our Racing Entitlements Contracts one driver would have to give up his seat for Marcos to come back but not one team chose to do so.

"And I totally understand their position. The Sydney Telstra 500 is the grand final of our sport and means an enormous amount for all of our teams and the drivers who compete all year.

"The right to race in the V8 Supercar Championship Series is a great privilege and while commercially they may have stood to gain, the value of being able to compete is far greater.

"It was not a decision of V8 Supercars Australia, we looked at it every way we could. In the end it just could not be done legally as the 30th REC had been wound up.

"Marcos is going to be at the Sydney Telstra 500 as our guest and we are excited and honoured to have him with us for this fantastic inaugural event."