The US Environmental Protection Agency (EPA) is willing to reconsider its guidelines for complying with new standards on diesel engine exhaust, the agency said in a court petition asking for proceedings to be postponed on a complaint from truck maker Navistar International.

In its request for a 60-day delay, the EPA said it would use the extra time to try to resolve the issues raised in Navistar's complaint, which was filed in March with the US Court of Appeals in Washington, DC Navistar's initial briefs to the appeals court are due on 20 November, Dow Jones said.

"The EPA intends to reconsider the guidance, which may lead to further agency action that could resolve some or all of Navistar's issues," the agency said in the petition filed 23 October. "Reconsideration of the guidance may lead to the very result Navistar is requesting" in its complaint.

A Navistar spokesman had no comment on the request. But Dow Jones suggested the company likely viewed the petition as a favorable development in its months-long battle against the EPA's certification of selective catalytic reduction, or SCR, as a strategy for complying with tougher standards on nitrogen oxide in diesel engine emissions.

Navistar, which is the only major truck maker using a different exhaust technology to meet 2010 emissions standards, has accused the EPA of disregarding its own procedures and requirements to accommodate truck makers wishing to deploy SCR on their engines. The company also said the agency provided a biased and incomplete record of the comments and concerns raised about SCR, which filters engine exhaust through a urea solution.

According to the report, Navistar particularly objects to an EPA provision allowing commercial trucks with SCR to operate for up to 1,000 miles once the urea solution has been used up. After that, the truck's engine would become inoperable. Navistar contends that truckers could undermine the effectiveness of the new regulations by repeatedly invoking the 1,000-mile exemption on SCR-equipped engines.