LOS ANGELES (AP) — West Coast seaports could shut down in as soon as five days — hobbling U.S. trade with Asia — if dockworkers and their employers cannot reach a new contract, the head of a maritime association warned Wednesday in remarks intended to pressure an agreement after nine months of negotiations. Operators of port terminals and shipping lines do not want to lock out longshoremen, but that would be inevitable if cargo congestion persists at ports that handle about $1 trillion in trade annually, Pacific Maritime Association CEO James McKenna said. The maritime association has been negotiating since May with the International Longshore and Warehouse Union, which represents dockworkers at 29 ports from San Diego to Seattle.