ABF Freight System has again lost a court challenge against the Teamsters Union and competitor YRC Worldwide for a second time.

The United States Court of Appeals for the Eighth Circuit has dismissed complaints it brought against the Teamsters and various YRC subsidiaries for violation of the National Master Freight Agreement, claiming the concessions the union made in its negotiations with YRC were not allowed under the the labor contract, according to a filing by ABF with the Securities and Exchange Commission.

The lawsuit was originally filed in November 2010, following concessions the YRC and the Teamsters negotiated in 2008, to help out the financially struggling carrier. This latest ruling is ABF's second court loss in the matter.

“ABF is disappointed in the court’s ruling and the fact that YRC received three rounds of concessions from the IBT that ABF did not also receive. ABF is assessing the opinion and determining whether to pursue additional options.” said ABF in the filing.

The news comes as ABF Freight System and the Teamsters union have reached another contract extension through September 30 as the two parties work through the process for resolving the two remaining supplemental agreements to the ABF National Master Freight Agreement. The agreement covers some 7,000 workers, including truck drivers.

The national agreement was approved on June 27 by a majority of Teamster employees. The seven supplements were initially voted down and re-voted over the past several weeks, with ballots counted last week.