By Bob Tita 

Paccar Inc. reported a 38% increase in first-quarter profit and said it expects sales of commercial trucks in the U.S. and Canada to remain at the highest level in nearly a decade.

Paccar, the maker of Kenworth and Peterbilt brands of trucks and the second-largest seller of the heavy-duty trucks in North America behind Daimler AG's Freightliner unit, easily topped analysts' first-quarter profit and revenue expectations. The company raised its industrywide sales outlook for the year, countering truck industry forecasters and analysts who have grown increasingly cautious recently about rising sales growth estimates, saying the truck market may be at a peak.

"We will see a reasonably good demand for trucks in the foreseeable future," said Paccar CEO Ron Armstrong during a conference call Tuesday with analysts. "As long as the economy continues at a good growth pace, there will be the need for the movement of goods. Freight numbers continue to be at or near record levels."

The company now expects industrywide retail sales of heavy-duty trucks in the U.S. and Canada this year to be in a range of 260,000 to 290,000 vehicles, up from its January forecast of 250,000 to 280,000 trucks. In 2014, 250,000 trucks weighing above 33,000 pounds were sold in the U.S. and Canada, the company said.

"The increase to industry forecasts was somewhat unexpected given the general, overall market sentiment and the conservative nature of management," said Stephen Volkmann, an analyst with Jefferies.

After years of sluggish, fitful demand for trucks that followed a long and steep sales slump, truck sales have been running at the highest volumes since 2006. Industry analysts have been focused on whether the elevated demand stems from trucking companies expanding their fleets, or simply replacing older, high-mileage vehicles with new models providing better fuel economy.

Mr. Armstrong said he's convinced that some of the increased demand is the result of fleet expansions to accommodate rising freight volumes that have been aided by lower diesel fuel prices. The fleet utilization rate in the trucking industry is now greater than 90%. Paccar said its first-quarter truck deliveries in the U.S. and Canada rose 31% from a year earlier.

Paccar said unfavorable currency-exchange rates trimmed first-quarter revenue by about $281 million. But the company said it benefited from a weaker euro against the U.S. dollar on imports of engine components into the U.S. from its DAF truck unit in Europe. Paccar said its truck sales during the quarter rose 13% to $3.77 billion, as pretax profit from trucks soared 60% to $339.1 million.

Overall for the quarter ended Jan. 31, Paccar reported a profit of $378.4 million, or $1.06 a share, up from $273.9 million, or 77 cents a share, a year earlier. Total revenue, which includes the company's financing arm, climbed 10.3% to $4.83 billion. Analysts had expected per-share profit of $1.01 and revenue of $4.68 billion.

In November, the European Commission charged that all truck manufacturers in Europe, including Paccar, had participated in anticompetitive practices. The commission said it would impose significant fines on the manufacturers. Paccar said it is preparing a response to the allegations, but provided no additional details about the investigation.

Paccar's stock was recently trading up 3.3% at $65.98 a share.

Angela Chen contributed to this article.

Write to Bob Tita at robert.tita@wsj.com

Access Investor Kit for Daimler AG

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=DE0007100000

Access Investor Kit for Daimler AG

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US2338251083

Access Investor Kit for PACCAR, Inc.

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US6937181088

Subscribe to WSJ: http://online.wsj.com?mod=djnwires