(Adds comments from company spokesperson, background) Feb 13 (Reuters) - Walmart Inc will close three of its U.S. technology hubs, asking hundreds of workers to relocate to keep their jobs, a company spokesperson told Reuters on Monday. Nearly all technology employees across the company would be expected to work in their offices for at least two days a week, added Robert Munroe, Walmart's director of global communications. The big-box retailer would close offices that housed technology staff in Austin, Texas, in Carlsbad, California and in Portland, Oregon, Munroe said.