April 29 (Reuters) - U.S. truckmaker PACCAR PCAR.O reported a decline in its first-quarter revenue and profit on Tuesday, hurt by a bumpy freight market in the face of tariff-related uncertainties, sending its shares down 8% in early trading.

The company, grappling with an excess supply of equipment amid slower demand within the machinery market, is now facing fresh challenges from the ongoing trade war, which has thrown the automotive industry and its supply chains into disarray.

PACCAR, which makes trucks under the Kenworth, Peterbilt and DAF brands, lowered the industry retail sales forecast for its Class 8 trucks in the U.S. and Canada to between 235,000 and 265,000 in 2025, from its prior expectation of 250,000 to 280,000.

"The North American truck market is being affected by uncertain economic conditions and the impact of new tariffs," said Kevin Baney, executive vice president at the company.

Class 8 trucks typically refer to those that have a gross vehicle weight of more than 33,000 pounds and are used to move heavy freight.

The Bellevue, Washington-based company posted a profit of 96 cents per share for the first quarter, compared with $2.27 per share a year earlier.

Excluding adjustments from a $264.5 million after-tax charge related to civil litigation in Europe, profit stood at $1.46 per share.

The company's revenue dropped 14.9% to $7.44 billion during the three months ended March 31.

(Reporting by Raechel Thankam Job; Editing by Shilpi Majumdar)

((RaechelThankam.Job@thomsonreuters.com))