UPDATE 2-Navistar 4th-quarter results top estimates

(Adds comparison to estimates)

NEW YORK Dec 30 (Reuters) - U.S. truck and engine maker Navistar International Corp (NAV.N) posted a quarterly net loss on Tuesday, reflecting asset impairment charges, but results before one-time items were better than Wall Street expected.

Navistar posted a fourth-quarter net loss of $343 million, or $4.81 per share, compared with a loss of $103 million, or $1.46 per share, a year earlier. Included in the net loss were asset impairment charges of $358 million, related to its diesel engine business for Ford Motor Co pickup trucks, the company said.

Stripping out one-time items, Navistar earned $1.31 per share, ahead of expectations for profit of 88 cents per share, according to Reuters Estimates.

The company said it increased military sales in 2008 and increased its market share in heavy-duty trucks.

Navistar did not immediately provide quarterly revenues, and a company spokesman said they were not immediately available. Analysts had forecast sales of $3.44 billion for the fourth quarter.

Navistar said it would provide its 2009 outlook next week. (Reporting by Nick Zieminski; Editing by Gary Hill)