After strong adverse reactions from their national Olympic committees. NATO nations began backing away today from suggestions that they boycott next summer's Olympic games in Moscow to protest the Soviet invasion of Afghanistan.

The suggestion was made and enthusiastically supported for further study, according to NATO and diplomatic sources, by representatives of a number of North Atlantic Treaty Organization countries at emergency meetings this week with U.S. Deputy Secretary of State Warren Christopher here and in Brussels.

It was among a wide range of possible retaliatory moves discussed by the allies. Others included seeking condemnation of the Soviet Union by the United Nations, for which diplomatic moves have already begun; stopping or reducing wheat sales by the United States and Canada; refusing to renew commercial credits the Soviets need to buy Western goods, and interrupting cultural exchanges.

But the Olympic boycott suggestion was quickly opposed today by Lord Killanin, president of the International Olympic Committee, and the presidents of national Olympic committees in the United States and throughout Europe. They said they would fight any boycott move and emphasized that only their committees, which are independent of government control and largely financed through private appeals, can decide who participates in the games.

Officials in several European countries then let it be known, publicily and privately, that their governments might not be so enthusiastic about the idea after all.

"This has gotten a bit out of hand," one official said, referring to the excitement the suggestion had stirred in the European press and some governments. "Serious doubts exist about governments ordering a boycott."

Several officials, insisted, however, that the allies remain determined to go well beyond protest notes in making a "firm and credible" demonstration of their opposition to the Soviet invasion of Afghanistan.

The angry reaction of many NATO officials to the invasion, according to sources, brought forth the suggestions of the Olympic boycott as symbolic of no longer "doing business as usual" with the Soviets. But the feasibility of the idea had not yeat been studied.

A West German government spokesman denied newspaper reports that its NATO ambassador was one of those who had suggested the boycott and had compared holding the 1980 Olympics in Moscow with holding them in Hitler's Germany in 1936.

The denial came after Willi Daume president of the West German Olympic Committee, said in a statement, "I once again speak against political pressure on international sport and the Olympic games. They are not the field on which political disagreements should be settled."

[ in Colorado Springs Colo., Don Miller, executive director of the U.S. Olympic Committee, said the committee is "diametrically opposed to the introduction of politics into the international Olympic movement." He said there appeared to be "many other alternatives" to consider before using the Olympics "as a tool for international politics."]

While members of the British Parliament from both the Conservative and Labor parties called today for either a boycott or cancellation of the Moscow Olympics, government ministers are known to have second thoughts about the feasibility of attempting either action.

Britain's Olympic chairman, Dennis Follows, said, "We would resist as strongly as we could any attempt by governments to interfere with us participating in the Olympics. It is not for governments to meddle in matters of this kind. I really do believe that sport is above all this carrying on.

"In the first place," he said, "I don't know how a boycott could be carried out. The only way the government can prevent us taking part is by taking away the passports of all our competitors. We live in a democracy and there is no way that is going to happen."

In france, where the national Olympic committee said NATO should have no influence over the conduct of the Moscow Olympics, government sources pointed out that it was not a pressing matter because the August games were a long way off.

The British Olympic Association's general secretary. Dick Palmer, accused NATO governments of considering a boycott of the Olympics because that would not risk the "serious repercussions" of breaking diplomatic or trade relations. "I object to politicians immediately turning to sport," he said, "and using it was a political football."

Palmer was referring to the boycott of the 1976 Olympic games by African countries, plus Guyana and Iraq, in protest of New Zealand's participation after its rugby team toured South Africa.

Britain has been warned by African politicians that it risks precipitating a similar walkout or being banned itself from the Moscow Olympics because it allowed a racially mixed South African rugby team to tour here last year. The Springbok rugby team of South Africa, banned from France because of fears there of Olympic consequences, also has been invited here by British rugby officials. This has renewed the protests and British government concerns.

The French newspaper Le Monde recalled that there was a similar campaign in the United States to boycott the 1936 Olympics in Berlin. But Avery Brundage, then American Olympic Committee president, insisted that the U.S. team participate.

Palmer, in Britain, objected to comparisons between the Berlin and Moscow games.

"I've been to Moscow five times for Olympic planning, he said, "and I have not seen any evidence that the games will be used for political purposes. The Russians want to stage the games well and project a good image, but so does every country that stages the games."

The Soviets clearly are treating the Olympics as an important showcase for Soviet socialism, are planning to control them closely and are making plans to remove many dissidents from Moscow.

Just yesterday, after the first suggestions of a boycott by NATO nations had been made, the Soviet news service Tass, noting that 200 days remained before the start of the games, reported that "more than 120 national Olympic committees reaffirmed participation of their athletes in the Moscow Olympics, which will probably be the most representative ones."

Soviet officials are fearful that the games might be spoiled by any kind of boycott. Although the Soviets reportedly worked behind the scenes to encourage the African boycott of the 1976 Olympics in Montreal, they have not been encouraging a similar reaction to Britian's contacts with South African rugby teams.

Killanin said that "I have always felt that at times administrators, and even international Olympic committees, forget that the athletes come first and in no way should be prevented from competing in an international competition by political, racial or religious discrimination."

He pointed out that invitations to the games can be accepted or refused only by national Olympic committees. Invitations for the Moscow Olympics will be formally extended at the end of this month.