By Lisa Baertlein

LOS ANGELES The National Retail Federation on Thursday said its members were "relieved" that U.S. West Coast seaport employers and the union representing 22,000 workers had reached a tentative deal, and urged both to quickly ratify the tentative agreement.

Retailers account for about 50% of container traffic that enters U.S. ports. Many shifted a portion of their cargo to ocean trade gateways on the East Coast and Gulf Coast to avoid potential slowdowns from the Pacific Coast labor talks that stretched 13 months before a tentative deal was announced on Wednesday.

"The West Coast ports are a critical artery for retailers and other businesses into the U.S. market," National Retail Federation CEO Matthew Shay said in a statement. "We urge the parties to quickly ratify the tentative agreement to bring certainty back to the West Coast ports."

The agreement comes as retailers like Walmart and Target are starting to land merchandise for the critical back-to-school, Halloween and Christmas retail shopping seasons. Manufacturers, automakers and food producers which import or export goods also rely on the West Coast ports.

The Pacific Maritime Association and the International Longshore and Warehouse Union late on Wednesday said they had reached a tentative deal on a six-year contract with assistance form Acting U.S. Secretary of Labor Julie Su.

Terms were not disclosed.

Dockworkers at 29 Pacific Coast ports stretching from California to Washington state, who had labored without a contract since July 1, had been seeking a bigger share of pandemic cargo surge profits and retroactive pay.

Frustrations reached a boil earlier this month after worker absences and terminal closures temporarily slowed or stopped cargo flows at key ports like Los Angeles/Long Beach, Oakland, California; and Seattle.

(Reporting by Lisa Baertlein in Los Angeles; editing by Jonathan Oatis)