AB Volvo said Monday it will acquire 34.5 billion yen of Nissan Diesel Motor Co.'s preferred stock and purchase 6 percent of Nissan Diesel's outstanding shares from Nissan Motor Co. -- a move that will push Volvo's stake in the truck manufacturer closer to 50 percent by April 2014.

Volvo decided to purchase 34.5 billion yen worth of the preferred shares from three banks and Nissan. They will be converted to a total of 165.1 million shares in installments between 2008 and 2014.

Volvo also exercised its option to purchase 6 percent of Nissan's shares in Nissan Diesel, which will increase Volvo's shares to 19 percent. In March, Volvo acquired 13 percent of the shares in Nissan Diesel from Nissan.