"We are studying the future course of the project but nothing has been decided. The cancellation of the tieup is one of the possibilities," a Nissan spokesman said.

Last month, Renault said it would spend 643 billion yen (5.4 billion dollars) buying minority control of Nissan and a stake in Nissan diesel.

The news agency Jiji press reported today that Nissan would break with Diamler Chrysler to underscore its alliance with Renault, which produces commercial vehicles in competition with the German-American rival.

Furious speculation about Nissan's truck division erupted this week after the Renault chairman Louis Schweitzer refused to rule out the sale of a 22.5 per cent stake in Nissan Diesel.

"Everything is possible, there would be buyers for Nissan Diesel," Schweitzer said in an interview with La Tribunebusiness daily published on Monday.

But such a sale "would only make sense if Nissan Diesel is not incorporated into Renault, truck division Renault VI as part of the Renault merger, he said.