U.S. presidential envoy Philip C. Habib met today with Philippine President Ferdinand Marcos and opposition leader Corazon Aquino in what the two foes described as a mission to gather information rather than an attempt to broker the country's simmering political crisis.

Neither side seemed to emerge from the separate sessions pleased with what each had heard from Habib on the dispute over an election marred by fraud and violence.

Habib's actions are being watched closely by all the participants in the current Philippine political drama after confusing U.S. policy pronouncements in which President Reagan first appeared to lean toward Marcos' version of recent events and then to stiffen his stance toward him.

Marcos, meanwhile, announced that Lt. Gen. Fidel Ramos will take over as acting military chief of staff on March 1. A press release said Ramos' takeover from hard-line Marcos supporter Gen. Fabian Ver -- a move seen as a concession to pressure from the opposition and from Washington -- will be delayed to allow a smooth transition.

Marcos said after two hours of talks with Habib at the Malacanang presidential palace that the U.S. envoy had assured him Washington "was not interested in any way in telling us how to run our affairs."

There were indications, however, that the session had not all been smooth. After their meeting, Marcos' aides described the encounter as "frank and cordial" and one said, "Our guy Marcos was rather terse."

A participant called the session "very pleasant" and quoted Habib as saying, "I've come here to listen and to render an assessment." Nevertheless, the participant went on to say Habib was "very cagey, very deliberate, very careful choosing his words."

An aide to Aquino expressed some surprise at Habib's reserve, saying, "We expected he was going to deliver some sort of message or propose something." Habib denied as "baseless" speculation that he is trying to broker a deal between the two sides, the aide said.

Aquino said she had stressed to Habib "that the crisis could only be resolved by a swift and orderly transfer to the Aquino presidency that the Filipino people have chosen overwhelmingly at the polls."

A participant in the meeting with Aquino said Habib stressed he was not carrying any message from Reagan or proposing any deal, but would "render an assessment" and make recommendations to Reagan on dealing with the Philippines.

Reagan said last Saturday that Marcos' ruling party was mainly responsible for widespread fraud and violence at the polls. Reagan said that electoral irregularities had been "so extreme that the election's credibility has been called into question."

Earlier, Reagan had blamed the fraud and violence on both sides in a statement that was widely interpreted here as accepting Marcos' version of events and as calling for cooperation between the two sides.

Marcos said he had given Habib pictures and documents on the conduct of the elections. Marcos said yesterday he had evidence that opposition supporters and members of a citizens' poll-watching organization, including priests and nuns, had committed most of the fraud and violence.

Neither side in the Habib-Marcos meeting would discuss what Habib had told Marcos about Reagan's view of the election and Marcos' situation. However, a spokesman for Aquino, Rene Saguisag, said Habib had explained to Aquino that Reagan's initial statement had meant to convey neutrality.

Saguisag, who attended the hour-long meeting with Aquino, said Habib had "conceded that better phraseology might have been used." Saguisag added that "all that Reagan, the great communicator, wanted to communicate, which he did not communicate very well, was an air of impartiality."

In a short statement after his meeting with Habib, Marcos quoted Habib as saying he is focusing his mission on the disputed Feb. 7 elections, which Marcos says returned him to power for another six years. Marcos indicated he had presented evidence to support his claim that Aquino's supporters were mainly responsible for the fraud and violence.

Aquino said her talks with Habib had focused on the tensions caused by the election, which she has insisted Marcos stole from her.

Habib also met with Cardinal Jaime Sin, leader of the Philippines' powerful Catholic Church, and was said to have scheduled meetings with election officials and business leaders in the coming days.

Habib and Marcos met alone for about one hour before being joined by U.S. Ambassador Stephen Bosworth and Philippine Acting Foreign Minister Pacifico Castro, the presidential palace said.

Aquino and Habib met along with Bosworth, the State Department's desk officer for the Philippines, John Maisto, and several top aides to Aquino.

In a barbed response to Reagan's most recent statement, Aquino said today that "what Reagan cited as 'the heartening evidence of the continuing commitment of the Filipino people to the democratic process' was a persecuted people clinging on the ballot boxes for their lives against a government determined to trample all over their rights."

"Nobody should think that a two-party system is now in place because the winning party has been cheated of its landslide victory," Aquino said in a press release. Aquino asked Reagan and his supporters "to imagine what their reaction [would have] been if an ally had asked them to accept that they had lost and settle down to being a good opposition."

Aquino continued to stress caution in her campaign to oust Marcos, even though aides acknowledged that many of her supporters were ready for more aggressive tactics.

Referring to yesterday's large demonstration here, in which Aquino announced boycotts against firms run by Marcos' supporters, Saguisag said "she knew a lot of the people wanted to march to Malacanang palace, but she was afraid of loss of life."

The effectiveness of the boycotts -- aimed largely at several banks run by the government or friends of Marcos -- was not immediately clear.

In Manila's gaudy Ermita district, though, many people criticized Aquino's call to shun the most popular brand of beer. "People are drinking it the same as before," shouted bartender Willie Romero over the din of his beer garden.

With only a short radio address today, Aquino kept her campaign to force out Marcos at a low key.