Truckers who haul freight from the ports of Los Angeles and Long Beach will go on strike against four ground-shipment companies on Monday, a Teamsters union official said, in a move that could revive labor tension at the nation's busiest cargo hub. Delegations of drivers planned to notify the companies of their intent to strike at 6 a.m. Pacific time, with picket lines going up immediately at the companies' truck yards, Teamsters spokeswoman Barb Maynard told Reuters. The strikers also plan to picket marine terminals, rail yards and other locations where the companies dispatch trucks, Maynard said. The truckers accuse the companies of wage theft by illegally misclassifying them as independent contractors…