Los Angeles, Dec 3 (IANS): Workers' strike over pay hike in America's busiest ports in Los Angeles and Long Beach has lasted for sixth day Sunday without a solution.

The Port of Los Angeles, the nation's busiest container harbour facility, and second-ranked Long Beach together handled over $400 billion in goods arriving or leaving the West Coast by ship, according to Los Angeles port spokesman Phillip Sanfield.

In addition, the two ports directly or indirectly support roughly 1.2 million Southern California jobs -- workers involved in moving freight to or from the shipping complex.

That does not count ancillary employment of people hired in restaurants, retail or other businesses that provide various services to those workers, Xinhua reported.

A national coalition of US business groups is urging an end to the strike amid fears that a prolonged strike will cost the US economy many billions of dollars. What's worse, it could even spread to the east coast.

Trade groups led by the National Retail Federation have sent letters to US President Barack Obama and leading members of Congress, asking them to intervene.

Those industry groups alleged that the strike has already cost $1 billion a day to the US economy.

The labor dispute has been triggered by 800 clerical workers at the ports. But they have the support of some 10,000 members of the International Longshore and Warehouse Union.

The strike, which started last Tuesday, has effectively shut down 10 of the two ports' combined 14 container terminals. Four other container terminals have remained opened, along with facilities for handling break-bulk cargo such as raw steel and tanker traffic.