President Reagan informed the Soviet Union yesterday that the administration has agreed to Moscow's request for a meeting in Geneva to discuss his decision to stop observing the limits of the unratified SALT II treaty, White House officials said.

The decision marked a shift from the administration's initial reaction to the Soviet proposal for a meeting of the Standing Consultative Commission, a joint U.S.-Soviet group established in 1972 to monitor the first SALT agreement. Top administration officials have been sharply critical of the commission, and at first talked about rejecting the Soviet proposal as a propaganda move.

The White House decision to attend the meeting is the latest in a series of attempts by the administration to send positive signals to Moscow concerning arms control and American desires for a second summit meeting between the president and Soviet leader Mikhail Gorbachev. Recently, for example, Reagan publicly described the latest Soviet arms control proposal as "the beginning of a serious effort" toward negotiations.

A White House official said Reagan informed the Soviets that the United States does not want the meeting to become a vehicle for publicizing Moscow's criticism of Reagan's May 27 decision on SALT II. The official said the U.S. role in a meeting, which the Soviets want to begin next week, would be to listen to Soviet questions about the SALT decision.

In a move that brought sharp criticism from Congress and the allies, Reagan decided that the United States would no longer be bound by the limits in the treaty -- which was signed in 1979 but never ratified by the Senate -- but would wait until later this year to determine whether the United States actually surpasses the limits.

Reagan said his action was based on Soviet violations of the treaty and indicated he would review Soviet actions in Geneva, and any change in Moscow's compliance practices, before deciding to actually exceed the treaty limits when the 131st B52 bomber is outfitted with air-launched cruise missiles, now scheduled for mid-November.

White House officials said the Soviets were notified through diplomatic channels yesterday of Reagan's acceptance. Separately, the president is preparing a letter to Gorbachev responding to the latest Soviet arms control proposals.

The Soviets sought the meeting on SALT II to get a clarification of Reagan's plans, in part because the U.S. decision on whether to break through the treaty limits in November or December appears to coincide with the time frame for a possible summit meeting.

It could not be learned yesterday whether U.S. officials intend to use the Geneva meeting to repeat administration charges that the Soviets already are in violation of the SALT agreement. A White House official said, "We have to see what they are coming up with first."

Deputy White House press secretary Edward P. Djerejian said yesterday that Reagan already has discussed his SALT II decision in public and private, and is willing to talk about it "obviously with the Soviets also." But Djerejian, in a briefing for reporters, refused to disclose the nature of Reagan's response to Moscow, saying the commission meetings are held in "strict confidentiality . . . even the fact that a meeting at times takes place is kept in confidence."

One explanation for Reagan's shift on the Geneva meeting is congressional debate over the SALT II decision and a Senate vote expected later this month on a nonbinding resolution calling on the president to reverse it. The resolution has bipartisan support from 48 senators, and backers predicted that if Reagan had turned down the Geneva meeting, the resolution would almost certainly get approval.

Top Reagan administration arms control policy-makers have looked with contempt in the past at this commission, saying it was ineffectual at resolving what Reagan alleges are serious Soviet violations of the treaty. Defense Secretary Caspar W. Weinberger called for the panel to be abolished in a report to Reagan before last November's summit with Gorbachev.

However, officials yesterday cited an instance before Reagan came to office when a special session of the commission called by the United States was used to get Moscow's explanation for several alleged violations. In 1983, the Soviets turned down a Reagan administration request for a special session to discuss violations.

Gen. Richard H. Ellis, former commander of the Strategic Air Command and the U.S. representitive to the commission, has repeatedly been criticized by top Pentagon officials for attempting to use the panel to resolve U.S. charges of Soviet violations without specific instructions from Washington.

Ellis is scheduled Tuesday to brief a group of senators who monitor the Geneva arms talks on Reagan's decision to allow U.S. representatives at the meeting.