Navigator Group Purchasing, a subsidiary of Managed Health Care Associates, has reached an agreement with Extendicare Health Services Inc. to purchase its group purchasing subsidiary, UHF/Star Purchasing Services, for $56 million. Upon completion, it would be Managed Health Care Associates’ third major GPO-related acquisition in a year. The deal would lay the groundwork for forming the biggest GPO serving long-term care, according to MHCA. Previously, Managed Health Care Associates purchased Navigator Inc. in December 2010 and Tidewater GPO in May. The Extendicare sale — comprising Star Purchasing Services and UHF Purchasing Services — is expected to close early next year, according to a statement from Extendicare Health Services’ parent company, Extendicare Real Estate Investment Trust.