CORONA, Calif.-Financially struggling Vista Hospital Systems is seeking to sell its three hospitals or refinance about $180 million in debt. The not-for-profit system is in exclusive negotiations with a buyer for its hospitals, said James Braley, a vice president of Cambio Health Solutions, Brentwood, Tenn., which manages the system's hospitals and is in charge of its sale or restructuring. Braley declined to discuss the potential buyer and would not comment on a published report that it is investor-owned Universal Health Services, King of Prussia, Pa. UHS officials did not return calls seeking comment. If a sale occurs, Braley said he doesn't expect the deal to close until the second half of 2003. Vista has turned around its operations but will require a debt refinancing or restructuring to show a profit, Braley said. The system lost $36.9 million for 1999 through 2001, the latest year for which final figures are available. Vista defaulted on $181.7 million in bonds in March 1999 and is not making debt-service payments under an agreement with its creditors, Braley said.