With mounting economic losses estimated at several billion dollars, the strike marks the largest cargo traffic disruption at the twin Southern California harbor facilities since a 10-day lockout of longshoremen at several West Coast ports in 2002.
Striking clerks remain at loggerheads with shippers and terminal owners over the future of union representation for jobs and hiring levels after employees retire. The International Longshore and Warehouse Union Local 63 had previously resisted calls for outside mediation.
The 800-member clerical workers unit of the ILWU local walked off the job last Tuesday, with some 10,000 longshoremen and other union members refusing to cross picket lines, forcing a shutdown at 10 of the twin ports' 14 container terminals.
Four other container terminals remained open, along with facilities for handling shipments of automobiles, liquid fuels and break-bulk cargo such as raw steel.
Unlike the labor clash a decade ago, which took place in the fall, the latest dispute is unfolding after the busy pre-holiday shipping season, limiting the scope of its ripple effect.
The brunt of the latest dispute at the two ports, which together account for nearly 40 percent of all U.S. cargo container imports, has been borne mostly by dock workers and truckers in the region. Terminal operators also worry about lost business as some cargo is diverted to competing ports.