HOUSTON, Jan 13 (Reuters) - U.S. oil and gas producer Chesapeake Energy’s Chapter 11 bankruptcy plan was approved by a U.S. judge on Wednesday, giving lenders control of the company and ending a contentious trial. Unsecured creditors unsuccessfully opposed approval, arguing the company had already designed a 2019 debt restructuring and delayed its filing to improperly benefit mutual fund provider Franklin Advisers Inc and other big debt holders. The plan would value Oklahoma-based Chesapeake at about $5.13 billion. Shareholders saw their investment wiped out with the bankruptcy filling.