MetroWest Medical Center has told employees it may end its contract with Blue Cross and Blue Shield of Massachusetts unless the insurer narrows the gap in payments between the hospital and its competitors, the Boston Globe reports. Leaders of the hospital and its physicians organization said rates paid for their services are as much as 40% lower than what other healthcare providers receive. MetroWest, owned by Vanguard Health Systems, operates Framingham (MA) Union Hospital and Leonard Morse Hospital in Natick, MA, which have a total of about 300 beds and more than 740 affiliated physicians.