White House counsel Lloyd Cutler, apparently indicating a change of policy, today left open the possibility that the United States would participate in the Olympic Games in Moscow this summer if there is a significant withdrawal of Soviet forces in Afghanistan.

At the same time the White House backed away from its original Feb. 20 deadline for full withdrawal of the troops.

Asked if the Carter administration would support sending a U.S. team to Moscow if Soviet troops were withdrawn from Afghanistan between Feb. 20 and May 24, the deadline for accepting invitations to the Moscow Games, Cutler said:

"If there were a bona fide withdrawal, or a plan for a bona fide withdrawal, it would have to be considered. After all, the objective of this in not to inflict a punishment but to achieve a result."

Cutler said the International Olympic Committee (IOC), meeting here before and during the Winter Olympics, should be given "a reasonable amount of time" to consider a U.S. proposal that this summer's Games be transfered from Moscow to another site, postposed, or canceled because of the Soviet invasion.

A delegration from the U.S. Olympic Committee (USOC) formally made that proposal to the full session of the IOC today, but urged members to defer a decision for a month or more in the hope that Soviet troops will be withdrawn in the interim, easing world tensions and allowing the Games to go on in Moscow with U.S. participation.

The White House, which had indicated there would be no extension of its Feb. 20 deadline appears now to have endorsed the USOC's strategy of biding for time. Cutler's statement today was the first high-level indication from the administration that a Soviet withdrawal after Feb. 20 might be acceptable to the U.S.

Carter also said the administration would allow the USOC "a reasonable amount of time" -- possibly until mid-April or later -- to accept or decline its invitation to participate in Moscow.

USOC Executive Director F. Don Miller said Cutler had assured him in two conversations this weekend that the USOC would not have to make an "urgent decision" about sending athletes to Moscow.

Miller said a decision to pull out of the Moscow Games was too important to be made by the USOC's Executive Board and would require a vote of the larger and more representative House of Delegates, which is scheduled to meet April 19 in Colorado Springs.

Miller said it would be "possible, but difficult," to convene the House of Delegates before then.

Cutler said "it would not necessarily be unreasonable" for the administration to wait until mid-April for a decision from the USOC, or even later of the IOC delayed for several months its decision on going forward with the Games in Moscow.

The USOC, in presenting its case that Moscow is now an inappropriate site for games dedicated to peace and goodwill, made clear its preference that the IOC delay a decision until the Soviet Union's intentions in Afghanistan are known.

"We would urge the IOC not to make a decision during this current session, but to take the time to review very carefully our presentation review the rules, and make a determination if there has been a violation of the foundamental principles of the IOC," Miller said.

USOC President Robert J. Kane said his group agrees with the administration that Moscow is not a suitable Olympic site "under current circumstances." But he said that if Soviet troops are withdrawn "the USOC position would change immediately."

Kane said he made it clear to IOC members during this morning's 90-minute presentation that the USOC had considered the issues fully and arrived at a point of view similar to the administration's, but had not "just capitulated to that point of view because it was governmental." IOC rules say national committees must be antonomous.

There was reports that the Soviet members of the IOC were pressing for immediate rejection of the USOC proposal.

Any IOC action other than flat rejection of the U.S. proposal would be interpreted as a moral victory for the U.S., and a softening of IOC President Lord Killanin's oft-stated position that it is "legally and technically impossible" to make a change.

Vitaly Smirnov, a vice president of the IOC and one of its two Soviet members learned today that his brother had died and was making plans to leave Lake Placid Tuesday. He reportedly has urged the IOC to make a decision before his departure.

IOC Director Monique Berliox said a vote on the matter was unlikely before late Tuesday afternoon because all 72 members present probably would want to express an opinion. Only 19 had spoken by 6 p.m. today.

A U.S. State Department spokesman said Secretary of State Cyrus R. Vance, whose highly political speech had upset many at the opening of the IOC session Saturday night, but left Lake Placid Sunday with "the distinct impression that the IOC was in a mood to delay a decision."

However, IOC member Willie Daume of West Germany said the international committee was moving toward rejecting the U.S. proposal, The Associated Press reported.

"We must oppose all kinds of boycott and demonstrate our independence," Daume was reported saying. "The American campaign has reinforced the Olympic movement.")

Kane suggested that the administration may have decided it needs more time to rally international support for its position.

Cutler said it is "well known that we are consulting with other interested governments, and they are consulting with us, on this matter. We expect support for a change of site, and for the decision not to participate, unless circumstances change, to grow."

Berlioux had characterized the U.S. government's position as "stiff and strong" and the USCO's as more flexible." Now the administration appears to have adopted the USOC's "wait and see" line.

President Carter said Jan. 20 that he would not support U.S. participation in Moscow unless Soviet troops were "fully withdrawn . . . within a month."

When a White House aide's personal opinion that U.S. participation might be supported if there were a "a real, legistimate withdrawal" at a later date was reported in The Washington Post several days later, that was promptly denied by the White House and State Department. It also was said there would be no extension of the Feb. 20 deadline.

Berlioux, in response to questions, said today that under IOC rules no U.S. journalists would be accredited for the Moscow Games if the U.S. does not participate, and that the $87 million in television rights and facilities fees NBC paid to the ICC and the Moscow Olympic Organizing Committee would not be returned.

NBC has said it will not televise the games if U.S. athletes do not take part. But it is insured for 90 percent of its $87 million investment by Lloyd's of London.