Nicole Maestri, Reuters, July 1, 2009 San Francisco - Wal-Mart Stores Inc, the world's largest retailer, said on Tuesday that it supports President Barack Obama's push to require large employers to offer health insurance to workers. "We are for an employer mandate which is fair and broad in its coverage," stated a letter addressed to Obama and signed by Mike Duke, the chief executive of Wal-Mart; Andy Stern, the president of Service Employees International Union (SEIU) and John Podesta, the CEO of the Center for American Progress. Wal-Mart's public statement of support for employer mandated coverage comes as Obama pushes for an overhaul of the $2.5 trillion US healthcare system. ... Wal-Mart