Nashville-based Columbia/HCA Healthcare Corp. (NYSE: COL) has signed a letter of intent with Santa Barbara, Calif.-based Tenet Healthcare Corp. (NYSE: THC) for Tenet to acquire Columbia's 80 percent interest in MetroWest Medical Center in Massachusetts. Terms were not disclosed. The transaction is subject to completion of due diligence by Tenet, negotiation of a final agreement and approval by regulatory authorities. MetroWest Medical Center consists of the 281-bed Framingham Union Hospital in Framingham, Mass., and the 194-bed Leonard Morse Hospital in Natick, Mass. The Medical Center had 1997 revenues of $169 million.