LISLE, Ill. (Reuters) - Navistar International Corp expects to report a net loss for its first fiscal quarter, which ended on Tuesday, due in part to troubles with a brake supplier that hurt its truck-making operations.

Chief Financial Officer Andrew Cederoth discussed the problem, which he said stopped production of some lines of its trucks, at a meeting with investors at the company's headquarters outside Chicago on Wednesday.

The issue is not limited to Navistar but also affecting other major truck suppliers, said spokesman James Spangler.

Analysts had forecast a first-quarter profit of 34 cents per share, excluding one-time items, according to Thomson Reuters I/B/E/S.

Earlier on Wednesday, Navistar unveiled a big push to expand into natural-gas-powered trucks.

Costs related to the brake issue are not included in the company's fiscal 2012 forecast, which called for adjusted earnings of $5.00 to $5.75 a share. Analysts on average were expecting $5.90 a share, according to Thomson Reuters I/B/E/S.

The company cited retiree health care costs and higher taxes as key reasons for be below analyst expectations.

Cederoth told analysts the company expected to make up the volume lost as a result of the idle lines later in the year. But he said it was too early to predict whether the company would be able to recoup the costs it is incurring as a result of the shutdown.

Dan Ustian, Navistar's chairman, president and chief executive, said it was also unclear how wide a loss the company would be forced to report in the quarter as a result of the brake issue because it was not clear how the company would account for it.

"What we don't know about is reserves," he said. "How is it going to be treated from an accounting standpoint?"

Ustian also said that Navistar was confident it would be able to comply with tough new federal nitrogen oxide standards for heavy-duty truck engines and avoid having to pay fines of as much as $2,000 a unit for any engines that fall short of the new rule.

But he said that if the company ran out of the pollution credits it has with the Environmental Protection Agency before its new heavy duty engine was certified by the EPA, it would pay the fines to be able to continue producing engines.

The credits allow engine makers that produced engines that exceeded earlier federal clean-air standards to temporarily sell engines that fail to meet current federal standards.

Ustian called the fines, officially known as non-compliance penalties, as Navistar's "Plan B."

"We don't ever plan on using Plan B," he said. "But that is Plan B and why it's out there - to take away that risk."

The EPA issued an emergency rule late last month creating the special fines for an unnamed truck-engine maker that it said was at risk of not meeting federal nitrogen oxide standards.

Ustian said Navistar had worked with the EPA to craft the emergency rule. (Reporting By James B. Kelleher; Writing by Scott Malone in Boston; Editing by Richard Chang and Tim Dobbyn)