Sales of medium- and heavy-duty trucks rose 25.4% in Canada last month vs. like-2009, marking the first gain for big trucks all year.

Increases in Class 8 and Class 6 deliveries offset declines in all other groups as April’s gain helped nudge Canadian big-truck sales into positive territory for the year, up 3.3% to 8,438 units.

Related document: Ward’s Canada Truck Sales by Weight Class – April 2010

Class 8 sales rose 53%, with all brands but Daimler AG’s Sterling and Volvo Truck North America Inc.’s Mack posting increases.

PACCAR Inc.’s Peterbilt posted Class 8’s largest jump – 221.5% – while Sterling recorded the biggest loss at 83%.

Medium-duty sales slumped 10.4%, with declines in Classes 4, 5 and 7.

Class 7 deliveries plunged 20.6%, with most manufacturers posting shortfalls.

Sterling, again, suffered the greatest drop on small volume, a similar situation seen at other declining brands.

Sales held steady at International Truck and Engine Corp., while PACCAR’s Kenworth gained 28.6%.

Class 6 benefited from the industry’s second-largest increase in April at 51.2%.

International’s 145.2% boost easily offset large percentage declines at many of the group’s truck makers.

Class 5 sales tumbled 22.4%, with segment-leading Ford Motor Co.’s 38.0% shortfall taking a significant bite out of the group’s volume.

Daimler’s Mitsubishi Fuso had the biggest percentage hike in Class 5, but on small volume.

Class 4 sales slipped 11.8%, despite a 19.3% hike at segment-leader Ford. General Motors Co.’s domestic and imported units fell 77.8% and 83.3%, respectively, on single-digit sales.

cschweinsberg@wardsauto.com