Updated

Negotiators for a clerical union and some of the world's largest shipping lines and terminal operators worked past a strike deadline Monday to try to reach a contract deal and avert a shutdown of the nation's largest port complex.

The union's deadline had been 12:01 a.m. Monday, but negotiations continued. Workers remained on the job Monday morning and there was no disruption of port operations.

John Fageaux Jr., president of the office clerical unit of Local 63, a division of the International Longshore and Warehouse Union, said the 750 clerks would strike if talks with employers at the ports of Los Angeles and Long Beach collapsed.

"We're in the process of presenting our last, best and final offer," he said. It could take several hours for the employers to review the offer after it is submitted.

Steve Berry, lead negotiator for the 14 marine terminal operators and other firms who employ the office clerks, wouldn't predict a timetable.

"We're working hard. We just keep going," he said.

The 15,000-member ILWU has indicated that longshoremen would honor picket lines if the clerks strike. That would effectively shut down loading and unloading operations at the neighboring ports of Los Angeles and Long Beach.

The port complex accounts for 40 percent of all the cargo container traffic coming into the United States.

A work stoppage could create ripple effects throughout many industries that depend on timely movement of cargo. It also would come as the ports enter their busy pre-holiday season, when shippers depend on the facilities to handle imports.

The clerks work at marine terminals and handle bookings for the export of cargo and other transport documents.

Under their most recent contract, full-time, port clerical workers earned about $37.50 an hour, or $78,000 a year. They also receive a pension, health care benefits free of premiums, and 20 paid holidays a year.

Berry said Monday that employers' latest offer included raises that over the life of a three-year contract would bump the employees' hourly pay to $39.50; the union is seeking increases that would equal $53 per hour by the last year of the contract.

In 2002, longshore workers across the West Coast were locked out for 10 days over a contract dispute. The shutdown cost the nation's economy an estimated $1 billion to $2 billion a day.