Formula One world champions Ferrari will start next season with an interim version of their F2004 car, according to chief designer Rory Byrne.

"The aim is to have the (new) car on track at the end of February," the South African told Sunday's Gazzetta dello Sport newspaper.

"We could bring it out from the first race of 2005 but we are not in such a hurry because we want to go deeper into research and design so that it is almost perfect when it does make its debut.

"We expect this to be between the third and fifth races."

The final 2005 race calendar has yet to be published but a draft version has the season starting in Australia on March 6 with races in Malaysia and Bahrain before France and San Marino in April.

Both Magny-Cours and Imola are listed subject to contracts being agreed.

Byrne said the car that would start the season in Melbourne would be "an interim version of the 2004 car, on which we will try and incorporate a good part of the aerodynamics of the new car."

He added that the engine will be updated to last for two races in a row, while the gearbox would be the old one.

Asked whether Ferrari could build a better car than the F2004, which won 15 of this year's 18 races on the way to the Italian team's sixth successive constructors' title, Byrne believed they could.

"The new car will represent another big step forward," he said. "But its success will depend on our rivals.

"It will be different to the F2004, but in an evolutionary sense. Some areas will be very different...the engine will be new, not interchangeable with the current one, as will the gearbox."

Byrne, who joined Ferrari in 1996 after helping Germany's Michael Schumacher to two titles at Benetton, said the new car would carry the stamp of his right-hand man Aldo Costa.

Costa is being groomed to replace Byrne when the designer's contract expires in early 2007.

"I could stay involved in a different manner," Byrne said of his future. "But from 2007 I will certainly spend most of my time in Phuket, in Thailand. My wife is from there.

"I have bought a 7,000 square metre plot by the sea and will build a holiday village with cottages for tourists."