AT&T (NYSE:T) said it now expects its proposed $39 billion acquisition of T-Mobile USA to close by the end of the first half of next year, a few months later than it originally planned, according to a regulatory filing. In a filing with the U.S. Securities and Exchange Commission, AT&T said the deal will close in the first half of 2012, pending regulatory approval. Previously, AT&T had anticipated the deal closing in March 2012. The Department of Justice sued in August to block the deal on antitrust grounds, and a trial is set to begin Feb. 13. AT&T first announced the deal in late March 2011. Article