Hundreds of millions of dollars worth of cargo is sitting on shipping docks in California because of a labor dispute that could cost the U.S. economy $1 billion a day. Workers were ordered off the job again Sunday after a breakdown in talks between labor and management.

The Pacific Maritime Association locked out more than 10,000 workers at 29 Pacific ports in a what it called a "defensive shutdown." The association represents shipping lines and terminal operators, and it says the lockout, the second in three days, will be indefinite. The association says the action was a response to a slowdown staged by workers.

White House spokesman Ari Fleischer said Monday the labor stoppage could hurt the U.S. economy and the Bush administration is watching it carefully.

The dispute is partly over benefits but mostly over a plan to introduce new technology. Pacific Maritime Association spokesman Steve Sugerman says management hopes to computerize the shipping process, of which much of the tracking is now done manually. "We need to bring these ports into the 21st century. That's the core of the issue in these talks," Mr. Sugerman said.

Tom Harrison of the Marine Clerks Union says the new tracking technology would allow some union jobs to be shifted from Pacific ports to so-called "right-to-work" states, where labor unions are weaker. "And one of these days, if it's Phoenix, Arizona or one of these right-to-work states, that won't even be cheap enough. They'll move it to Bangladesh, India, or some other place. And that is not right," Mr. Harrison said.

Los Angeles, Long Beach and other Pacific ports together process $300 billion a year in cars, computers, food and other goods.

Port management is demanding that the workers extend a contract that expired July 1st before returning to the job. Negotiations were set to continue Monday afternoon in San Francisco.