BP Plc (BP/) , which has paid more than $28 billion for the 2010 Gulf of Mexico oil spill, asked a Texas court to let it tap into $750 million in Transocean Ltd. (RIG) ’s insurance policies on the doomed Deepwater Horizon rig. BP filed claims with Transocean’s carriers in 2010, seeking to tap a $50 million primary policy issued by Ranger Insurance and $700 million in excess coverage from Lloyd’s of London and other underwriters. The carriers asked the court overseeing the spill litigation to rule that BP wasn’t entitled to unlimited access to Transocean’s insurance. BP lost its battle for coverage at a lower court, won reversal on appeal, then saw that victory erased last year as the U.S. Court of Appeals in New Orleans withdrew its original opinion. The panel sent the case to the Texas Supreme Court , which held oral arguments today in Austin, […]