WARRENVILLE, Ill. (AP) -- Heavy truck and parts manufacturer Navistar International Corp. said an improving economy and more orders for large vehicles such as school buses should help it boost profits this year.

The company said Tuesday it expects to earn between $388 million and $466 million in net income, or between $5 to $6 per share, during its 2011 fiscal year ending Oct. 31. The forecast excludes transition costs associated with the integration of the company's truck and engine engineering operation and the potential positive impact of income tax valuation adjustments. '

Navistar earned $233 million, or $3.05 per share, in 2010.

Analysts had been expecting adjusted earnings of $362.1 million, or $4.68 a share, for the current fiscal year, according to FactSet.

Navistar makes heavy vehicles like school buses and military transport

The company said its results should be buoyed by an overall increase in orders for heavy rigs. It said it was revising upward its estimate for total industry retail sales of large trucks and school buses in the United States and Canada. It expects sales to be between 240,000 to 260,000 units for the fiscal year. That would be up from 191,300 units during 2010.

The company expects to pay between $75 million and $80 million to integrate truck and engine engineering operations into a single facility. Including those costs, net income would be between $311 million and $388 million, or $4 to $5 per share.

Shares of Navistar rose $3.26, or 5.5 percent, to close at $63.09.