The Soviet Politburo formally endorsed today Foreign Minister Andrei Gromyko's report on his talks with President Reagan and reaffirmed Moscow's "readiness for a serious, businesslike dialogue" with the United States.

The Soviet leadership accepted Gromyko's assertion that his talks with Reagan and Secretary of State George P. Shultz "did not reveal any signs that the United States intended to "adjust its policy course toward realism and peacefulness." But a communique asserted that the Soviet Union would welcome a normalization of Soviet-American relations on the principles of equality, mutual respect and noninterference in each other's internal affairs.

"The U.S. government's readiness to act in this way will always meet a proper response from the Soviet side," the Politburo statement said.

The statement and remarks by a Soviet official at a press briefing omitted standard Soviet charges that the Reagan administration was bent on pursuing military supremacy.

Political observers here interpreted today's pronouncements as a signal to Washington that Gromyko had full authority during his discussions with Reagan and other U.S. officials and that Gromyko's views on these talks have been accepted by the ruling council.

Underscoring this assessment was a hastily convened press conference by the Soviet Foreign Ministry during which foreign and Soviet journalists were briefed on today's Politburo meeting several hours before the official communique was issued by the government news agency Tass.

Vladimir Lomeiko, a senior Foreign Ministry spokesman, also offered the first positive Soviet comment on Gromyko's talks with Reagan and Shultz. "The fact in itself that the meetings took place and that they involved a detailed exchange of views is important and useful," he said.

The only critical remarks involved an assertion that Washington's policy "has dangerously enhanced world tensions and disrupted international relations" and that Moscow wanted to see an "adjustment" of this U.S. policy course to open the way for a resumption of dialogue.

Lomeiko repeated Gromyko's statement in Washington last week that the future will tell whether Reagan's overtures would be translated into action.

"At this time it is not a desire to have negotiations that is most important, but a desire to have specific negotiations with a view of reaching a specific agreement," Lomeiko said.

Diplomats said that today's Soviet comments tend to confirm an impression that Moscow was more receptive to Reagan's new positions and that last week's contacts -- despite the absence of visible results -- may help ease the impasse in Soviet-American relations sometime in 1985.

According to this view, the Soviets also may have sought today to allay speculation in the West over possible differences within the Soviet leadership over Moscow's policy toward the United States.

There have been no indications of any split in the Kremlin on this issue in recent days. Some obervers here believe that differences may have existed some time ago and that they played a role in the dismissal last month of Marshal Nikolai Ogarkov, the former Soviet chief of staff.

Ogarkov was a vigorous advocate of military interests, arguing publicly for new and more powerful weapons to confront the Reagan challenge.

The Politburo, in what may be a move to display unity, today praised Gromyko's "great work" at the United Nations and in Washington last week.

"Conversations with President Ronald Reagan and other American representatives displayed the Soviet Union's readiness for a serious, businesslike dialogue with the American side," the communique continued.

"One has to state that a far-reaching exchange of views on key issues of Soviet-American relations and, in this connection, on the state of world affairs, did not reveal any signs that would attest to the real intention of the American side to adjust its policy course toward realism and peacefulness.

"Declarations of a general nature about the benefit of more constructive relations with the Soviet Union, made by the American side, are not backed by specific deeds.