Volvo trucks can come with bunks, fridges and cooking equipment

Pre-tax profit was 4.02bn kronor ($507m; �287m) in the three months to 30 September from 1.52bn a year ago.

Earnings last year suffered from a 1.31bn kronor charge relating to a revaluation of Volvo's bus business.

Analysts welcomed the figures, but said they were concerned that the company was forecasting flat sales growth in the US and Europe next year.

Limit to growth

"The single most important aspect is that the market looks stronger this year, which is positive," said Fredrik Westin, an analyst at West LB.

"But at the same time they see a flat market in the US next year, and that is a little bit of a disappointment," Mr Westin said.

The company, which owns the Renault, Mack and Volvo brands, tried to play down their worries.

"There are those who are disappointed that the US market is seen flat next year, but based on a 25% increase this year, the US market simply can't grow any more," said chief executive Leif Johansson.

The company, which sold its car brand to Ford in 1999, said that European sales will increase by 5% this year, compared with 25% growth in the US.

"We were slightly negative about Europe in the second quarter, but in the third quarter Europe has come back," Mr Johansson said.