Updated

Anthony Principi (search), chairman of the commission that will review the newly released list of military base closings, has resigned his executive post with the drug manufacturer Pfizer (search) Corp.

Principi, a former Veterans Affairs (search) secretary, told the company Friday that he was stepping down in order to fully carry out his responsibilities as chairman of the Base Realignment and Closure Commission. He cited the time demands of the commission job.

Word of Principi's resignation came Monday as the commission was opening hearings on Defense Secretary Donald H. Rumsfeld's proposal to close 33 major facilities and realign hundreds of others to save billions of dollars.

Principi joined Pfizer as a vice president in March, to run the company's Washington, D.C. office. He is from California, a state that was hard hit in the previous four base closing rounds. And Pfizer has a large research facility in Connecticut, a state hurt the most in the Pentagon's base closing recommendations released Friday.

"We're very sorry to be losing Mr. Principi, but we respect his commitment to the commission and to the president and to the Congress in service of our country," said the Pfizer spokesman, Paul Fitzhenry.

Principi, a decorated Vietnam War veteran, once served as a chief counsel for the Senate Armed Services Committee and Senate Veterans Affairs Committee. He also has been a top official with defense contractor Lockheed Martin.