Sales of medium- and heavy-duty trucks in Canada rose 35.3% December.

Although it was a decline from November’s 40.7% hike, December still was one of the year’s best months and good enough to push 2010 calendar-year big-truck volume 21.9% ahead of 2009, Ward’s data shows.

Class 4 deliveries slipped 3.1%, making it the only segment in the red. Class 8’s 40.6% jump tied with Class 6 in December.

But for the year Class 8 had far and away the biggest increase of sectors in the black, up 40.5%.

In December, Daimler AG’s Freightliner brand and Volvo Truck North America Inc.’s like-named brand posted triple-digit percentage increases in Class 8, with the latter up 329.6%.

PACCAR Inc.’s Kenworth saw the largest gain among Class 8 brands in 2010, up 81.4% from 2009.

Total medium-duty truck sales rose 25.7% in December, but for the year the group fell 3.0%.

Thanks to positive performances at all but General Motors Co. and Ford Motor Co., Class 7 sales rose 25.7% from like-2009. Freightliner posted the biggest increase, up 125%.

Freightliner also was the leading gainer for the year in Class 7, with sales soaring 80.6% from 2009.

Class 6’s 40.6% rise in December was thanks to Freightliner’s 241.2% jump.

Daimler’s Mitsubishi Fuso brand posted the largest percentage gain in Class 6 in 2010 but on much lower volume than Freightliner, which rose 114.5%.

A variety of triple-digit percentage increases powered Class 5’s 30.6% rise in December. Mitsubishi Fuso posted a whopping 419.2% increase on 35 sales. Volume-leading Ford rose 130.4%.

Ford also was the Class 5 volume-leader for 2010, with 1,362 sales, up 6.4% from 2009.

But Isuzu Motors Ltd.’s 323 units vs. 42 in 2009 gave it Class 5’s largest increase, 669%.

Class 4 sales slipped both in December and in 2010, down 3.1% and 4.7%, respectively.

Isuzu’s imported units posted Class 4’s biggest increases in both December (170%) and in 2010 (207.4%).

Total medium- and heavy-duty trucks sales in Canada last year tallied 28,688 units, ahead of 2009’s 23,532 units but still below the 39,701 big trucks sold in 2008, Ward’s data shows.