LOS ANGELES — Troubles on the West Coast waterfront are getting worse.

Amid an increasingly damaging labor dispute, 29 West Coast seaports which handle about $1 trillion of goods annually will be mostly closed four of the next five days.

The announcement came Wednesday from the association representing companies that operate marine terminals where dockworkers move containers of goods on and off massive ocean-going vessels, eventually transferring the containers onto trucks or trains for distribution nationwide.

Companies said they won’t hire crews to load or unload ships Thursday, Saturday, Sunday or Monday — when they’d have to pay presidents’ day holiday or weekend wages to dockworkers they accuse of slowing their work to gain leverage in contract talks.

Employers do not want to pay hourly rates that are at least 50 percent above normal, which would bring a few of the highest-paid dockworkers to close to $100 per hour, according to Steve Getzug, a spokesman for the Pacific Maritime Association.

Instead, terminal operators could decide to hire smaller crews that would focus on moving already-unloaded containers into the flow of commerce. Full crews would still service military and cruise ships, and any cargo ships bound for Hawaii — but these are small operations compared to work on container ships that are as long as some skyscrapers are tall.

Those ships bring in car parts, furniture, clothing, electronics — just about anything made in Asia and destined for U.S. consumers. Ships then take goods back, exports that include perishables such as rice, hay, nuts and produce.

Cargo has been struggling for months to cross the docks amid historically bad levels of congestion.

Employers blame crowded docks on longshoremen they say have staged work slowdowns since November; dockworkers deny slowing down and say cargo is moving slowly for reasons they do not control, including a shortage of truck beds to take containers to retailers’ distribution warehouses. In recent days, the International Longshore and Warehouse Union said companies are exaggerating to cut dockworker shifts and pressure negotiators into a contract agreement.

In response to Wednesday’s move by employers, the union noted that longshoremen were not hired to load or unload vessels last weekend. It also emphasized that the two sides have not talked across the bargaining table since last Friday.

“The union is standing by ready to negotiate, as we have been for the past several days,” union President Robert McEllrath said in a written statement. He suggested the maritime association is “trying to sabotage negotiations.”

Whatever the causes of the congestion, containers that used to take two or three days to hit the highway have been taking a week or more. Meanwhile, outside ports in Southern California, the San Francisco Bay Area and Washington, about three dozen ships are at anchor, awaiting a berth.

Differences over what is causing the cargo backup reflect disputes at the bargaining table.

Negotiations between the maritime association and dockworkers’ union for a new contract were to resume Wednesday in San Francisco, but were canceled despite heavy — and increasing — pressure from elected officials and businesses to reach a deal. The two sides are now scheduled to reconvene Thursday morning, maritime association spokesman Getzug said.

Talks have stalled over how to arbitrate future workplace disputes. Some of the biggest issues, including health care, have been resolved with tentative agreements.