Marcia Smith, the longtime exec director of the Screen Actors Guild Foundation, has resigned.

She will be replaced on an interim basis Monday by former SAG contract chief Sallie Weaver.

Smith, who has been in the top slot at the 25-year-old foundation since 1995, did not give a reason for her departure.

“I am pleased to assist the SAG Foundation on an interim and part-time basis during this time of transition,” Weaver said in a statement. “During this short period, I can only hope to follow in Marcia Smith’s footsteps in delivering the programs she implemented, with such excellence, on behalf of the public and performers.”

The nonprofit foundation is funded and governed independently of SAG. Programs include emergency assistance to actors in times of financial and medical distress; a scholarship fund, LifeRaft, Conversations and Casting Access seminars and workshops; an online storytelling project; and BookPALS (Performing Artists for Literacy in Schools) with 2,200 volunteers.

The foundation also opened an Actors Center in 2008 in the SAG HQ, offering use of a screening room, editing bays, and workshop space. The foundation raised more than $1.2 million in relief funds for actors during the 2000 strike against the ad industry, with Nicolas Cage, Harrison Ford, Helen Hunt, Eddie Murphy, Kevin Spacey and Bruce Willis all making six-figure gifts to the fund.

Weaver worked for two decades at SAG and departed in 2006 as the deputy national exec director of contracts. She then worked as a consultant at Entertainment Strategies Group with SAG national exec director David White, then formed Entertainment Labor Consulting.