Top officials of the government of President Corazon Aquino told Secretary of State George P. Shultz today that there is no basis for "a substantive negotiation" with communist-backed rebels in the Philippines despite recent contacts aimed at starting "preliminary" peace talks, according to senior aides to Shultz.

The assessment, attributed by the U.S. aides to Aquino, Defense Minister Juan Ponce Enrile and Armed Forces Chief of Staff Gen. Fidel V. Ramos, all of whom met privately with Shultz today, suggested that the chances are slim for negotiating an end to the insurgency.

Enrile, in a public appearance before a Manila business group, said it would take "a miracle" to bring an end to the fighting through a political solution. In remarks that appeared to cast greater doubt than ever before on government-rebel negotiations, Enrile said "my personal honest opinion" is that real Marxists can not be won over through dialogue.

Earlier this month, Aquino announced that the communists had named a fugitive former journalist as its representative to cease-fire talks with the government. The announcement, at a news conference marking her 100th day in office, was the first sign of movement toward a cease-fire between the more than 200,000-strong armed forces and the estimated 16,500 rebels of the New People's Army, the armed wing of the Communist Party of the Philippines.

Shultz, at a press conference late today, called the Aquino government's approach to the rebels "a sensible strategy" that is "not that different" from U.S. policy in Central America.

Shultz applauded the willingness of the Aquino government to offer dialogue to the Philippine rebels but pointedly said any talks should be "not about power sharing" but about "the return of people" from the rebel ranks to the legally recognized political process.

The central demands of the Communist Party, the New People's Army and associated groups are reported to include representation in a coalition government and expulsion of the United States from two large military bases, Clark Air Base and Subic Bay Naval Base. The Communist Party has named former journalist Saturnino Ocampo as its chief negotiator. The government's negotiators have not been announced.

According to a senior U.S. official who briefed American journalists, the Philippine leaders who talked to Shultz are "very realistic" about the potential advantages and outcomes of negotiations.

The Philippine government leaders "don't expect it the insurgency is going somehow to fade away or that there is any real basis for a substantive negotiation with the insurgency, because the demands of the insurgency are such as to be basically nonnegotiable," said the U.S. official who sat in on Shultz's round of talks today.

What the Aquino government is trying to do, the official added, is to demonstrate it has "gone the extra mile" toward permitting armed guerrillas to rejoin open and legitimate politics. The official said, however, that he did not expect the government to begin "a serious negotiation" on the agenda indicated recently by the insurgents.

Shultz, who has expressed approval for political, economic and military reforms undertaken since Aquino replaced Ferdinand Marcos in February, seemed to dispute a recent Pentagon assessment that the military situation "is serious and getting worse."

Shultz' impression, he said, is that such a guarded assessment as the one offered June 3 by Assistant Secretary of Defense Richard L. Armitage in congressional testimony is not the "general view" in Manila.

Repeating his earlier declaration in New York that "I'm bullish on the Philippines," Shultz said "additional progress" has been made in solving the problems of this nation since his last trip about six weeks ago. Both Shultz and his aides suggested that a greater degree of self-confidence than before was evident here.

During a two-hour luncheon meeting with Aquino, attended by only three people on each side, Shultz extended an official invitation for the Philippine leader to come to Washington in late September.

Shultz said specific dates are being worked out and that he hopes announce the visit shortly.

Neither the future of the U.S. military bases in the Philippines nor the future of Marcos was discussed in the talks today, Shultz said.

In New York, Mary Bautista, a member of the Commission on Good Government that was set up by the Aquino government to recover what it describes as Marcos' "ill-gotten" wealth, said the government has so far recovered about $75 million in cash and $175 million in real estate and other assets, Reuter reported.