Fairfax County Supervisor Martha V. Pennino (D-Centreville) plans to ask the county Board of Supervisors today to replace School Board member Carmin C. (Chuck) Caputo, sources close to the supervisors said yesterday.

Caputo, the School Board vice chairman, has been a member since 1980 and his second full term expires July 1. Caputo would not comment yesterday on reports he would be replaced, but he said he has not asked to leave the board.

Pennino also would not comment on the reports. The identity of the reported successor and the reason for the reported shift could not be learned yesterday.

Caputo was nominated to the School Board by Pennino to represent the Centreville District in 1980. The county board, which meets today, traditionally honors the wishes of supervisors in appointing School Board members from their home districts. Members are paid $5,500 a year.

Caputo, an electrical engineer for Defense Department who moved to Fairfax 20 years ago, would be the second School Board member ousted in recent weeks. The supervisors voted last month to replace Robert E. Frye, an at-large member of the School Board, with Frank Francois, a businessman.

Francois was supported by Republicans on the Board of Supervisors, who gained a majority on the county board last November for the first time in more than a century.