Nissan Motor on Tuesday said it would sell 13% of Nissan Diesel to Volvo AB, according to The Associated Press (AP).

Japan's second-largest automaker is the top shareholder of Nissan Diesel, with a roughly 19% stake in the truck maker, the nation's fourth-largest, the report noted.

Volvo has an option to buy an additional 6% stake, Nissan CEO Carlos Ghosn said at a press conference held in Japan on a national public holiday.

The news agency said there had been speculation that the automaker wanted to sell Nissan Diesel shares as it sees little benefit in having a truck company, whose earnings tend to fluctuate dramatically in its group.

"Today it's time to envision a new role for Nissan Motors and a new partner for Nissan Diesel," Ghosn told the conference, adding: "Volvo is a very natural pick."

In a statement cited by The Associated Press, Volvo said it and Nissan Motor have also agreed to review areas of cooperation, together with Dongfeng Motor in commercial vehicles in China - Nissan Motor owns 50% of Dongfeng Motor.

AP noted that Renault holds a 44% stake in Nissan and about 20% of Volvo's stock, and that Renault sold its truck division to Volvo in 2001.

Last month, Nissan Motor announced it would build light trucks for sale by Renault in Europe.