Struggling No. 1 U.S. trucking company YRC Worldwide Inc has asked investment bank Rothschild to evaluate potential bond exchanges as part of its restructuring plans, according to a source familiar with the matter.

Rothschild was retained early this year by Overland Park, Kansas-based YRC, but has only recently been asked to take a more active role, the source said.

Rothschild which specializes in mergers and acquisitions and restructuring, including providing bankruptcy advice.

A bond exchange could be announced as early as five to six weeks from now, the source said.

The vast majority of YRC's $2.55 billion in debt is in loans, with $392 million in bonds outstanding.

YRC has also been working with financial advisory firm Tenex Capital Management for six months on restructuring plans.

According to the source, who was not allowed to discuss the matter on-the-record, all of the plans Tenex has worked out with YRC are focused on restructuring outside bankruptcy court.

The source described Tenex's involvement as consensual -- as it has been approved by YRC's creditors -- and the company has advised the trucking firm on cost cutting, negotiations with the Teamsters union on wage concessions and talks with lenders on amendments to its credit facility.

YRC is a less-than-truckload company, which consolidates smaller loads into a single truck.

So far this year YRC has secured seven amendments to its $950 million credit facility from creditors, persuaded the Central States multi-employer pension fund to take property instead of cash for pension payments, plus convinced its Teamster union-represented workers to take a 10 percent pay cut in return for a 15 percent stake in the company.

The company has also worked to streamline its national network by shutting facilities and shedding jobs.

In late June YRC said it would start talks on a fresh round of concessions from the Teamsters.

Like the rest of the U.S. trucking sector, YRC has been hit by falling freight volumes and weak pricing.

(Reporting by Nick Carey; Editing by Richard Chang)