Fitch upgrades Delphi ratings following acquisition

May 15 (Reuters) - HICAGO, May 15 (Fitch) Fitch Ratings has upgraded the ratings of Delphi Financial Group, Inc. (DFG) and its insurance subsidiaries following completion of the acquisition of DFG by Tokio Marine Holdings, Inc. (TMHD) and its subsidiary Tokio Marine & Nichido Fire (TMNF). The ratings are removed from Rating Watch Positive and assigned a Stable Outlook. A complete listing of rating actions follows at the end of this release. TMNF is the largest property/casualty ins