Porter J. Goss was forced to step down yesterday as CIA director, ending a turbulent 18-month tenure marked by an exodus of some of the agency's top talent and growing White House dissatisfaction with his leadership during a time of war.

The likely successor to Goss is Gen. Michael V. Hayden, the former director of the National Security Agency and now deputy to Director of National Intelligence John D. Negroponte, senior administration officials said. He could be named as soon as Monday.