Less-than-truckload carrier ABF Freight System Inc., the largest subsidiary of Arkansas Best Corp., said today it has sued the Teamsters Union, rival YRC Worldwide, and YRC's subsidiaries for violating the current National Master Freight Agreement (NMFA), the collective bargaining agreement covering most of the nation's unionized trucking employees.

In a statement, Fort Smith, Ark.-based ABF argued that the three rounds of concessions the Teamsters have granted to YRC— the most recent being announced on Saturday—run counter to the agreement's basic premise that it should apply equally to all the companies that signed it.

"We need a long-term, industrywide solution that is fair to all NMFA parties," said Wesley Kemp, ABF's president and CEO. "We have the obligation to our employees, to our customers, and to Arkansas Best shareholders to enforce our rights under the NMFA and compete on the same playing field with our industry peers."

In May, Teamsters at ABF declined to ratify a proposed agreement that included labor concessions similar to those agreed to in late 2009 by YRC workers. The dual actions left ABF at a significant cost disadvantage to YRC.

The legal action, filed administratively under the contract and in federal court in Arkansas, seeks $750 million in damages. It contends that the Teamsters and YRC acted illegally by entering into "concessionary side agreements" with YRC to the exclusion of ABF and other companies governed by the NMFA.

"These agreements led to ongoing significant wage and benefit reductions and other economic concessions that were applied only to YRC, and not ABF," ABF said.

Besides the financial damages, ABF has requested the creation of a "grievance review committee" to hear the complaint and resolve the dispute, or to have the contract amendments benefiting only YRC declared null and void by the court.

In a statement, the Teamsters called the suit "frivolous and without merit." YRC had no comment at press time.