LOS ANGELES » Labor talks are resuming in an effort to end a strike that shut down most of the terminals at the nation’s busiest port complex, the Los Angeles and Long Beach harbors, officials say.

A strike launched by 70 clerical workers on Monday led to a massive backup on Thursday, after the strike expanded to shutter seven of eight Los Angeles terminals and three of six Long Beach terminals. Dockworkers from their union refused to cross their picket line.

The lead negotiator for the Los Angeles/Long Beach Harbor Employers Association Stephen Berry said he wrote a letter to the union president Thursday afternoon to invite him back to the negotiating table with no preconditions.

International Longshore and Warehouse Union spokesman Craig Merrilees confirmed a meeting would take place later Thursday to discuss the contract dispute clerical workers and 14 shippers have been locked in for 2 1/2 years.

The status of any talks wasn’t immediately clear early Friday. Representatives for both sides didn’t immediately respond to phone messages requesting updates on any negotiations.

Earlier in the day, at least 18 ships docked and inside the adjacent harbors were not being serviced, port spokesman Phillip Sanfield said.

Talks broke off Monday and the workers struck at a single terminal but expanded the picket lines Wednesday, even after an arbitrator ruled the walkout invalid on Tuesday.

Combined, Los Angeles and Long Beach comprise the nation’s busiest port complex, handling 40 percent of the nation’s import trade.

There was no immediate word on how much the strike is costing the ports. November generally is a slower time for the ports because most holiday goods already have been shipped ashore.

However, there were concerns that a continued widespread strike could prompt retaliation from terminal operators. A bitter 10-day lockout at a number of West Coast ports in 2002 caused an estimated $15 billion in losses.

At issue is the union’s contention that terminal operators have outsourced local clerical jobs out of state and overseas — an allegation that the shippers deny.

Striking clerical worker Trinie Thompson, 41, said Thursday afternoon that her fellow strikers do work at computers — such as collections, customer service and setting up container movement — that can be handled from anywhere, and employers were taking advantage of that to use non-union workers overseas.

"We’re definitely concerned about the outsourcing of jobs here," said Thompson, who added jobs were being sent to Costa Rica, India and Taiwan. "We need to keep the jobs here in the United States."

The negotiating group for the shippers has denied any local union clerical jobs were outsourced. The shippers, in turn, claim that the union wants contract language to permit "featherbedding" — the practice of requiring employers to call in temporary employees and hire new permanent employees even when there is no work to perform.