ABF Freight System is taking its challenge to competitor YRC's deal with the Teamsters union to the U.S. Court of Appeals.

In November, ABF Freight System filed suit against rival YRC Worldwide and the Teamsters aimed at blocking a labor agreement central to YRC's survival.

That move came after the Teamsters membership ratified a "restructuring plan" aimed at saving more than 25,000 union jobs. It was the third round of union concessions at the struggling LTL carrier.

But ABF says that's not fair to the other less-than-truckload competitors that are also covered under the National Master Freight Agreement.

"It is ABF's firm belief that the three rounds of concessions granted to YRC ... by the IBT are in violation of the NMFA that has been in effect since April 2008," said Wesley Kemp, president and CEO, ABF Freight System. "The NMFA applies equally to every company that signed it and quite simply, with these three amendments, it does not do that."

However, in December, a federal judge dismissed the lawsuit. U.S. District Judge Susan Webber Wright granted motions by YRC and the Teamsters to dismiss the suit, saying ABF did not have jurisdiction to sue over the agreement.

"ABF respectfully disagrees with the court's decision last month," the company said in a statement. "Therefore, we have chosen to exercise our right to file an appeal."