MANILA, JULY 31 -- A top-ranking military officer in charge of Manila's security predicted today that coup attempts will diminish now that the new Congress has successfully opened and a renegade colonel has been arrested.

Also today, the presidential commission charged with tracking the "hidden wealth" of former president Ferdinand Marcos and his business cronies filed its last three civil suits against the deposed president and more than 300 of his associates, including a member of the new Senate. Today's action brought to 35 the number of suits that have been filed seeking the return to the Philippines of more than $96 billion.

Brig. Gen. Alexander Aguirre, commander of the capital's security forces, said Monday's arrest of Col. Rolando Abadilla, believed to have masterminded at least five coup plots, was "a major blow to the extreme rightists."

Abadilla, former intelligence chief under Marcos, has been linked to coup plots that involved a takeover of the Manila Hotel last July, a siege on a suburban television station in January, an attack on Army headquarters in April and an aborted attempt to seize American and other foreign hostages at Manila's International Airport and the International School earlier this month.

Abadilla formally was charged Thursday with conspiracy to commit rebellion in connection with the plot to seize the airport and school, the adjacent Air Force headquarters and other government facilities in an effort to topple the government of President Corazon Aquino. Aguirre said on July 13 that the plan had been "pre-empted" by the arrest of an Armed Forces major and his confession.

Aguirre's announcement of the plot followed the release in Washington of tape-recorded conversations of Marcos boasting to a man posing as an arms dealer, about a planned invasion of the Philippines using a $25 million arsenal of tanks, mortars and Stinger antiaircraft missiles.

Abadilla was the principal tactician for the plotters over the past 17 months, but also was intricately involved in the strategic planning for the coup attempts, Aguirre said today.

Each coup attempt was timed to cause disruption to a major event in the Philippines' recent post-Marcos history, Aguirre said. The January television station siege was aimed at disrupting a national plebiscite on a new constitution, the revolt in April at the May 11 national elections and the plot to seize the airport at the opening of Congress last Monday, Aguirre said.

This morning at Camp Aguinaldo, the main military headquarters, the Armed Forces chief of staff, Gen. Fidel V. Ramos, accused small factions within the military of still trying to "destabilize" the government by circulating anonymous "poison letters" among the troops. The most recent letter, signed by the so-called "Grand Opposition," asked the soldiers to overthrow Aquino's government because of alleged electoral fraud.

Aguirre predicted, however, that with the convening of Congress and the arrest of Abadilla the threats will diminish. "The coup plots will be very negligible," he said. Aguirre dismissed widespread rumors of yet another coup attempt planned for this weekend.

Today the government filed suit against Sen. Edgardo Angara, who ran as one of Aquino's handpicked candidates for the Senate. Angara, a former law partner of ousted defense minister Juan Ponce Enrile, is the only member of the Senate accused of aiding Marcos' cronies in amassing "ill-gotten wealth."

Enrile also has been named in several suits. He is awaiting the outcome of a complicated recount of votes for the 24th and final Senate seat, which he claims to have won in May's election.