Beth Israel Deaconess Medical Center, one of Harvard's major teaching hospitals, is negotiating with a Stanford physician to become its next CEO. The board this week offered the job to Kevin Tabb, MD, CMO of Stanford Hospital and Clinics in California, according to two people close to the process who wish to remain anonymous because they are not authorized to speak. But, they cautioned, the board and Tabb are still working out salary and other details of his employment contract. Hospital officials would not comment yesterday. Late Wednesday, after a board meeting, chairman Stephen Kay e-mailed a statement to Beth Israel Deaconess employees saying that the board had closed in on a leading candidate. "In the next few days, you may hear or read in the media about who will be BIDMC's next president and CEO," he wrote. "Please know that while we are closer to naming a new leader, there are important steps the board and a leading candidate must take before this action becomes final."