CHICAGO — Military and export truck shipments continue to drive the growth strategy of Navistar International, despite softness in traditional markets, the company reported Tuesday.

The company expects “expansionary shipments” of 40,000 to 45,000 vehicles this year will account for a third of Navistar’s total worldwide vehicle shipments and help to mitigate the current weakness in its core markets.

“The commercial truck market is beginning to improve slowly but clearly it is still tough going,” said Daniel C. Ustian, Navistar chairman, president and CEO. “To help offset cyclical downturns, our strategy has been to build successful and sustainable businesses in military and export markets. That strategy is paying off in the success of these expansionary businesses. And we are well positioned in our truck and engine businesses with strong pro ducts to respond to demand when the market does recover.”

Navistar’s defense business is expected to consistently generate $1.5 billion to $2 billion in annual revenue going forward, Ustian said.

Navistar’s fiscal first quarter results reflect the soft market experienced through January. Worldwide shipments of school buses, Class 6-7 medium trucks and Class 8 heavy trucks and expansion market vehicles for the three months ending January 31 totaled 18,720 units, down 37 percent from 29,680 units shipped in the same period a year earlier when totals benefited from a historic pre-buy in advance of 2007 emissions standards.

The company plans to become current by mid-year in its financial filings with the Securities and Exchange Commission.

Meanwhile, the truckmaker has named Josef (Joe) Kory VP of global distribution operations for its parts distribution and sales organization, Navistar Parts.

Kory, who has 18 years of industry experience, previously was general operations manager for Paccar Parts.