China's SAIC Motor and Iveco, Italian auto giant Fiat's truck and engine manufacturing unit, said Tuesday they planned to expand their joint venture's product line to seize growth opportunities.

SAIC and Iveco planned to extend their cooperation beyond light buses and heavy-duty trucks to make large and medium-sized buses, special vehicles and core components, the companies said in a joint statement.

The two have agreed to build jointly a technical centre and integrate their resources in China to create "a domestically leading and internationally competitive large-scale commercial vehicle company."

They said they aimed "to seize the good opportunity of the Chinese commercial vehicle market development, and continuously meet the demands of high-quality and full-range commercial vehicles," according to the statement.

No financial details were provided.

The announcement came after Volkswagen, Europe's biggest automaker, said last week it would invest four billion euros (5.8 billion dollars) in China over three years to develop new products and increase production capacity.

China's total vehicle sales outstripped those of the United States for the first time in January to make the Asian giant the world's largest car market, helped by Beijing's efforts to stimulate domestic consumption.

The nation's auto sales soared 81.7 percent in August from a year earlier to 1.14 million units, breaking the one million unit mark for a sixth consecutive month, according to figures from an industry association.

Iveco has a joint venture with SAIC Motor in Chongqing city in southwestern China that makes heavy-duty trucks.

In late 2007, its parent Fiat withdrew from a loss-making car venture with China's Nanjing Automobile after the firm merged with SAIC Motor.