MANILA, AUG. 20 -- Half the Philippine Senate voiced support today for a bill to ban nuclear weapons from the Philippines, where the United States has two large military bases that anchor the Pentagon's Pacific defense strategy.

The bill, filed today and referred to the Foreign Relations Committee, would outlaw the storage or possession of nuclear weapons "in whole or in part" and would forbid the transport of nuclear arms "into the country or within its territorial waters whether in transit or disembarkation." The ban would apply also to the transport of nuclear weapons through Philippine airspace.

U.S. officials, following standard policy, have refused to confirm or deny the presence of nuclear arms in the Philippines at Subic Naval Base, home of the 7th Fleet, and Clark Air Base, headquarters of the 13th Air Force. But Philippine officials and military analysts believe nuclear devices are stored at, and transported through, both facilities.

U.S. officials in Manila and at the State Department in Washington declined immediate comment on the bill.

Presidential press secretary Teodoro Benigno said that President Corazon Aquino had not been consulted on the legislation, which was sponsored by 10 members of her ruling Lakas ng Bayan party. Benigno said it would be "premature" for the president to comment on the bill.

The Philippine president has said she will keep her "options open" on the question of whether to extend the lease on the U.S. bases. The current lease expires in 1991, and will require a treaty ratified by the Philippine Senate for an extension.

Twelve of the Senate's 24 members, including Aquino's brother-in-law and five former Cabinet secretaries, said they will vote for the nuclear ban. The bill was introduced by Sen. Wigberto Tanada, a left-wing lawyer who said he favors removal of the bases, and cosponsored by several political moderates close to Aquino.

Under the new constitution, 12 votes are enough for Senate passage. If the House of Representatives also passed the bill, Aquino could either sign or veto it. A two-thirds majority of both houses is required to override a veto.

Supporters of the bill suggested they do not feel the approval of a nuclear ban would seriously effect relations with the United States.

"It's not my intention to vote against the bases. I will vote for this bill without tying up my hands on the bases issue," said Sen. Heherson Alvarez.

But Sen. Neptali Gonzales, vice chairman of the Senate Foreign Relations Committee, said passage of the legislation would probably result in the withdrawal of U.S. bases from the Philippines. "This is a matter to be given serious consideration," he said.

Alvarez said he believes "most Filipinos would prefer to keep the bases." He said the proposed nuclear ban could be used for leverage in renegotiating the bases lease.

Several senators said they believed the bill was merely an attempt to pass into law a provision in the new constitution that reads: "The Philippines, consistent with the national interest, adopts and pursues a policy of freedom from nuclear weapons in its territory."

Aquino's critics on both the left and right maintain that the government is bound by the provision to enforce a nuclear ban at U.S. bases in the Philippines. But Aquino supporters who favor keeping the bases contend that the phrase "consistent with the national interest" would allow the government to reject a nuclear ban.

After New Zealand banned visits by nuclear-armed or nuclear-powered ships, the United States suspended the South Pacific nation from the ANZUS defense alliance.