STOCKHOLM (AP) _ Swedish truck and bus maker AB Volvo said Friday its fourth-quarter profit fell 15 per cent to 2.99 billion kronor ($388 million US) as higher costs for product launches offset rising sales.

The company's more closely watched pre-tax profit dropped 10 per cent to 4.14 billion kroner ($539 million), against analysts expectations of a rise to 5.15 billion kroner ($670 million).

Shares in Volvo, one of the world's largest truck makers, fell 7.7 per cent to 349 kronor ($45.42).

Volvo also took a 550-million-kronor ($71-million) writedown of its stake in the holding company that owns struggling U.S. school bus maker Blue Bird.

Sales for the quarter rose 15 per cent to 65.29 billion kronor ($8.47 billion).

The Gothenburg-based company raised its forecast on the market for heavy trucks in North American to between 330,000 and 340,000, but maintained its forecast for 270,000 trucks in Europe.

``We expect continued high demand in the next quarters,'' said CEO Leif Johansson.