LOS ANGELES >> Federal mediators have offered to get involved in negotiations to resolve a labor dispute between longshoremen and shipping lines that threatens to disrupt movement of goods through West Coast ports.

The U.S. Federal Mediation and Conciliation Service said Tuesday it will reach out promptly to both sides. No scheduled talks were immediately announced.

The offer follows a request for mediation from the Pacific Maritime Association, which represents shipping lines and cargo terminal operators.

Longshoremen who load and unload cargo at 29 ports from San Diego to Seattle have been working without a contract since July.

Shippers say both sides remain “far apart” on many issues. As talks have lingered they have accused the longshoremen of a work slowdown.

The ports provide a key trade link with Asia.