MANILA, JAN. 26 -- President Corazon Aquino's top aide today accused military authorities here of wiretapping the telephones of high-ranking government officials, and said the United States had bugged Aquino's phone during her official U.S. visit in September.

Executive secretary Joker Arroyo told reporters that he staged a call to the president during her stay in New York to "placate" eavesdropping Americans. "We assumed there was an American bug. We knew there was a Philippine bug," Arroyo said.

Arroyo, speaking to a breakfast forum, accused the Defense Ministry here of wiretapping his home phone and the phones of other officials. "We asked the armed forces, and more particularly the Defense Ministry, to secure our phones," he said. "They left bugs. That is unpleasant but that is the truth. I repeat, instead of securing and removing the bugs, they placed bugs."

The remarks appeared to indicate widespread wiretapping of government officials in one ministry by officials in another. Arroyo and other aides said they were considering legal action against those responsible for the taping and for distributing copies of one taped conversation to the media.

Arroyo called the taping an "embarrassment" to the government and a serious breach of national security.

His comments were part of a new palace offensive aimed at limiting the political damage from the disclosure last week of secret tape recordings of a private conversation he had last September with Aquino and presidential speechwriter Teodoro Locsin, who were both in New York at the time.

During that conversation, according to copies of the tape and transcripts released to reporters, Aquino and the aides discussed the implications of an independent commission's vote to make the Philippines a "nuclear free" country in its new constitution. The three expressed fears that an aid bill in the U.S. Senate might be imperiled by the vote, and Arroyo suggested telephoning a commission member.

The disclosures are potentially damaging here since Aquino has repeatedly said that she did not try to influence the constitutional commission's deliberations. Also, any hint of American involvement in the Philippines' internal affairs immediately raises fears that the former colonial power is trying to manipulate events here.

Arroyo said today that the taped conversation did indeed take place, although he added that some portions of the tape appeared to have been spliced and thus taken out of context. He refused to specify where he thought the tapes had been spliced and what material was excluded.

He explained the conversation by saying that the three had "assumed" their conversation was being secretly recorded by American officials during Aquino's U.S. visit. After the commission vote to make the Philippines "nuclear-free," Arroyo said, they decided to stage the conversation to make it appear to the eavesdropping Americans that Aquino was really concerned and would try to have the vote reversed.

"The conversation was for American consumption," Arroyo said, in what amounted to the unusual charge that one government had eavesdropped on the leader of another during an official state visit. "We assumed that there was an American bug," he said, adding that he knew all along that his phone was simultaneously being monitored by the Philippine military.

Locsin, in a lengthy letter sent to a local newspaper and published today, said that a request for a sweep of bugs would have been "impolite and impolitic," so the president's party "assumed" that the phone was monitored. He said at least three parties were listening to every call -- the party making the call, the party receiving, "and an American and/or Philippine bug."

{State Department spokeswoman Nancy Beck said she had no immediate comment. "I simply have nothing for you on that," she said.}

The tape and a transcript of the September call were released by former member of parliament Homobono Adaza, a mercurial opposition figure who is believed to be trying to discredit Aquino less than two weeks before a scheduled plebiscite on the draft constitution.

Adaza, who has promised to release more tapes, tonight called the palace's explanation "ridiculous."

Military officers have denied making the tapes, and Adaza said he did not obtain his copies from military sources.

The next tape scheduled for release, according to several impartial sources who either have heard it or were told of its existence, apparently involves a close relative of Aquino's discussing the Moslem situation with a high-ranking U.S. Embassy official here.

Arroyo left open the question of whether the taping was still going on. But the conversation between the Aquino relative and the embassy officer apparently took place only about three weeks ago, the sources said.

Diplomats and other sources here said they believed ex-president Ferdinand Marcos left behind the remnants of an extensive wiretapping system aimed against his political enemies -- most of whom are now in government. The bugging apparatus is probably still in existence, they said, although they doubted that the intelligence and security agents still on the military payroll here had the capability to continue widespread, around-the-clock taping of the entire government.

Arroyo said that when he talks to friends on his phone, he routinely asks, "Rex Robles, are you listening?" Rex Robles is a Navy captain closely identified with Juan Ponce Enrile, who Aquino ousted as defense minister last November.

At the presidential palace, another Aquino aide, national affairs adviser Aquilino Pimentel, was asked if he knew his phone was bugged and he replied: "Of course," adding that he rarely discusses sensitive matters on the telephone.