[USA] A federal judge in San Francisco ruled yesterday that a sex-discrimination lawsuit against Wal-Mart Stores Inc. could proceed to trial as a class action because of evidence the nation's largest employer paid female workers less and gave them fewer promotions than men. The suit could include as many as 1.6 million current and former female Wal-Mart employees...[also refers to Sam's Club (part of Wal-Mart) Home Depot, Texaco, Coca-Cola, Publix Super Markets]