Renault Formula One team mechanic Steve Larney of Ireland balances a wheel on a Michelin-shod wheel at the Indianapolis Motor Speedway June 29, 2006. REUTERS/John Gress

By Alan Baldwin

LONDON (Reuters) - Michelin has no interest in supplying tires to Formula One unless the sport agrees to make them bigger, a change motorsport head Pascal Couasnon feels sure will happen eventually.

The French company and current suppliers Pirelli are the only bidders for the three-year contract from 2017, when rule changes could be introduced to make the cars quicker and harder to handle.

Michelin have stressed that their bid depends on a change of tire specification from 13 inch to at least 18.

"If the sport decides to stay with 13 inch, we respect it but it would not make sense to us," Couasnon told Reuters during the season-ending London round of the new electric Formula E series.

"That’s where we are going to wait for the next time (the contract is up for tender)," he added when asked what would be the response to no change.

Michelin supply 18-inch tires to the world rally and endurance championships and Formula E.

The current FIA tender document opens the way for an increase in diameter "if the tire manufacturer feels there may be advantages to the competitors by doing so."

Couasnon said the transfer of technology was important for Michelin and F1 tires needed to have a smaller sidewall and be more similar to those used by regular drivers as well as longer-lasting.

"We don’t want a banal tire. We want a tire that is getting close (to road tires) so then you can transfer," he added.

Whereas the Pirelli F1 compounds have been engineered to degrade and increase the strategy options, Couasnon said Michelin were not prepared to make a tire that wore out quickly.

"It’s not the message we want to give which is ‘we’re going to invest a lot of technology to make a tire which doesn’t last’," he said.

"I respect the strategy of my competitors but that’s not really the image and philosophy of Michelin.

"We can create pitstops with some other ideas but what Michelin would like to deliver first is a tire where the driver has fun and is tired at the end of the race. Today they are not."

Drivers regularly complain that the current rules force them to look after fast-deteriorating tires and ease off the throttle to save fuel, and that the cars are not as challenging to drive as they were.

Asked whether he felt the switch to larger tires would have to come one day, Couasnon replied: "I am convinced."

Jean Todt, president of the governing International Automobile that drew up the tender documents, told Reuters it would be inappropriate for him to make any decision on the matter.

"It is important that it is addressed by people with more skill than I have about the size of the wheels," said the Frenchman.

Michelin withdrew from Formula One in 2006, a year after a farcical U.S. Grand Prix that went ahead with only six cars after all the Michelin-equipped teams withdrew on safety grounds.

Formula One has had a sole supplier since then, with Bridgestone replaced by Pirelli in 2011.

Couasnon was confident the memory of the 2005 race in Indianapolis would not be held against Michelin now.

"I remember 2006 was pretty good. We’ve learnt quite a bit from this event. We’ve done Silverstone for many hours and didn’t have any issues. For me that’s the past," he said.

"I hope that people will remember more what we’ve done over the last two or three years and what we are prepared to do for tomorrow."

(Reporting by Alan Baldwin, editing by Justin Palmer)