The chairman of the Senate Intelligence Committee urged President Reagan yesterday to try to persuade Philippine President Ferdinand Marcos to step down.

Sen. David F. Durenberger (R-Minn.) added his voice to a rising crescendo of congressional criticism following widespread reports of fraud in the Feb. 7 balloting.

"By all independent estimates, Mr. Marcos clearly lost the election," Durenberger said. "Nevertheless, by use of fraud on a scale that would scandalize a Chicago ward heeler, he has claimed a tainted 'victory' " over opposition candidate Corazon Aquino."

Durenberger said Reagan, as "a longtime friend" of Marcos, "is the one person who may be able to persuade Marcos that it is time to step aside."

"The president must make that effort while exploring ways to render Mr. Marcos' departure as honorable and face-saving as possible," the senator said.

Last fall, Durenberger's committee released a report predicting that Marcos would be driven from office within three years unless he undertook major reforms. Durenberger said at the time he doubted that any reforms would be forthcoming.

Yesterday the senator said, "We must act now. Time is on the side of the communists and other radical forces in the Philippines. The sooner a solution is found, the more likely that solution will be a democratic one."

The Philippines is a key U.S. ally and home to the two largest American military bases abroad.

Durenberger's appeal came a day after a House subcommittee voted 9 to 0 to halt direct U.S. aid to Marcos' government and instead channel the money to nongovernmental agencies, including the Roman Catholic Church.

As Durenberger revealed his appeal to Reagan, the chief of the technical team of U.S. observers of the Philippine election said Marcos is closely following the U.S. reaction, particularly Congress'.

Allen Weinstein, president of the Center for Democracy, was part of a team of U.S. observers led by Sen. Richard G. Lugar (R-Ind.) and Rep. John P. Murtha (D-Pa.). He met earlier this week with Marcos in Manila.

In a pre-election meeting, Weinstein recalled, Marcos "predicted the American government wouldn't believe the figures, they would be so huge" for him.

But the criticism surprised Marcos, Weinstein said, and the observer added that the Philippine president "is clearly working the situation on a day-to-day basis."

At a news conference, Weinstein declined, however, to predict what Marcos might do should Congress halt U.S. aid.

Weinstein said Marcos' government and his ruling KBL party "sought through manipulation of the electoral process, intimidation and fraud to obtain the reelection of Ferdinand Marcos."

"In the process, there occurred the systematic disenfranchisement, both by design and administrative disorganization, of millions of previously registered Filipino voters," he said.

The State Department said yesterday that Marcos is sending three representatives to the United States for talks with administration officials.

Department spokesman Charles Redman said Labor Minister Blas Ople, Ambassador to the United States Benjamin Romualdez and presidential aide Alejandro Melchor will arrive in the United States during the weekend.

Romualdez is Marcos' brother-in-law.

"They have requested meetings with a number of officials next week," Redman said.

He declined further comment on the requests or who will meet with the visitors.