Jacob Terner, the founder of struggling Prospect Medical Holdings Inc., is stepping down as chief executive and turning over the day-to-day reins to the CEO of a recent acquisition.

Sam Lee will take over as chief executive for the Culver City-based Prospect, the company announced Monday. Lee, 41, was president of Alta Hospitals System LLC when Prospect acquired it last August and has since served as the subsidiary’s chief executive.

Terner, 73, will continue as executive chairman of the company he founded in 1987. Prospect Medical Holdings operates four community hospitals in the greater Los Angeles area and manages a network of more 9,000 physicians who are part of independent physician associations or medical clinics.

Prospect also has a 38 percent stake in a partnership that owns Culver City’s Brotman Medical Center, which in October filed for Chapter 11 bankruptcy protection after its senior lender cut off funding. The hospital retained Navigant Capital Advisors to explore alternatives that could include the hospital’s sale.

Prospect has delayed filing its 2007 annual report, which was due Dec. 31 for its fiscal year ended Sept. 30. The company is restating Alta’s pre-acquisition financial statements for 2006. Prospect also announced Monday that the review was complete, and the company expects to be caught up on its filings by the end of April.