Coastal Physician Group's president and chief executive officer, Joseph Piemont, quit last week without explanation.
His departure came three weeks after shareholders elected two new board members, shifting control to associates of former President and CEO Steven Scott, M.D.
In May, the board voted to put Scott, Coastal's founder, on a sabbatical leave from the top post.
A committee led by Coastal Chairman Jacque Sokolov, M.D., and Scott, who is still a board member, will search for a permanent replacement for Piemont.
Meanwhile, Henry J. Murphy, one of the new board members, was named interim president and CEO. Murphy worked for consulting firm Arthur Andersen for about 33 years, ending in 1994. His last post was director of Andersen's North American corporate recovery services.
Also, board member Norman H. Chenven, M.D., resigned, citing other business commitments. Chenven, CEO of Austin (Texas) Regional Clinic, said he regretted having to step down at a time when the board was coming together to pursue common objectives.
Coastal, based in Durham, N.C., is attempting to return to profitability after a series of business problems. It's also searching for a buyer.