Mack Trucks‘ deliveries continued to slump in December, dropping 36 percent from the same month in 2006, Mack’s parent company Volvo AB reported Wednesday.

The month-to-month comparison, however, ended an otherwise very bad year on a positive note. The Allentown company delivered 1,721 trucks in December, a 12 percent increase over its performance in November.

In 2007, Mack delivered 18,600 trucks, about half as many as the year before. The company’s woes were the result of market forces that affected the entire U.S. trucking industry. Stricter emission rules that took effect in January caused truck sales to plunge. Buyers had stocked up on trucks in 2006 before the more expensive 2007 models hit the market.

The company initially expected the slump to last six months, but then the housing market went bust. Heavy-duty trucks are used in the construction and freight industries, both of which have slowed, as well as in the garbage industry.

Mack braced for a downturn in fall of 2006 by announcing it would lay off some of its 1,040 workers at its Lower Macungie Township plant. The company eventually laid off 350 employees.

Mack has benefited from an uptick in its foreign business — especially as the declining value of the dollar has increased overseas demand for U.S products. Yet, even after tripling in the past four years, international sales remain a relatively small part of Mack’s total revenue.

”Looking ahead to 2008, assuming no major changes in the economy, we anticipate the total market for heavy-duty trucks in North America to be similar to the one experienced [last] year,” Mack spokesman John Walsh said in an e-mail.

Volvo, which sold its car division to Ford Motor Co. in 1999, is the world’s second-largest truckmaker behind DaimlerChrysler AG. In Europe, Volvo trucks also sell under the Renault Trucks brand, and the company’s other businesses include buses, construction equipment and engines.

In addition to its Lower Macungie plant, Mack employs about 1,000 people at its Allentown headquarters and testing site.

In other company news, a strike at a Dublin, Va., Volvo plant that makes Mack highway trucks continues. The United Auto Workers union, representing more than 2,600 members at the plant, called the strike last week after its contract expired.

The plant’s production is at a standstill.