The nine European Common Market countries moved closer to President Carter's position on an Olympics boycott today, warning the Soviet Union that it must reduce international tension and "create conditions so that everyone can participate" in the summer Moscow games.

Stopping short of an outright threat to boycott the games if Soviet troops are not withdrawn from Afghanistan, the foreign ministers of the market countries decided to set a final joint policy on participation at their next meeting Feb. 18 and 19 in Rome, after watching what the Soviet Union now says and does and how the United States responds.

At that meeting, the nine members of the European Economic Community -- Britain, France, West Germany, Italy, Ireland, Belgium, the Netherlands, Luxembourg and Denmark -- also hope to announce a comprehensive list of responses to the Soviet invasion of Afghanistan.

These are likely to include, in addition to the policy on the Olympics, limits on preferential trade credits to the Soviet Union and a variety of efforts to link the Common Market more closely to Third World nations.

In effect, the Common Market countries are tying their joint decision on the Olympics to Carter's Feb. 20 deadline for a Soviet withdrawal from Afghanistan, although the foreign ministers would not publicly acknowledge the coincidence in timing or state whether a Soviet withdrawal was necessary to "create conditions so that everyone can participate" in the Olympics.

Earlier today, the leaders of France and West Germany issued a joint warning to the Soviet Union that detente would not survive another shock like the Soviet invasion of Afghanistan.

Washington Post correspondent Ronald Koven reported from Paris that the joint declaration ending a three-day meeting of West German Chancelor Helmut Schmidt and French President Valery Giscard d'Estaing called for a Soviet withdrawal from Afghanistan. However, it made no mention of sanctions if Soviet troops remained in the south Asian country.

Giscard later gave a briefing for French correspondents in which he explicitly said he opposes the kinds of retaliation against the Soviet Union that President Carter has taken.

There was still disagreement here in Brussels on whether boycotting the Olympics was a good idea or whether the nine European governments could convince their athletes and national Olympic committees to go along with a boycott even if it became Common Market policy.

Only West Germany indicated that it would be likely to join the U.S. government moves to boycott the Olympics.

"Because of Berlin and everything, can you imagine us going to Moscow if the United States stays home?" one West German official asked rhetorically.

Britain has been campaigning to have the Olympics moved or postponed but if it is not certain it could or should try to stop its athletes from competing in Moscow if the games go on as scheduled.

As current spokesman for the market's foreign ministers, Attilio Ruffini of Italy said they were "agreed in emphasizing that it was solely the Soviet Union which has destroyed the conditions which must prevail for the holding of the Olympic games."

He said the international tension caused by the Afghan crisis was "of such magnitude" that it was destroying "the sporting spirit" of the games.

But Ruffini added that the Soviet Union "still has time to remove these obstacles." A spokesman for the West German foreign minister, Hans-Dietrich Genscher, added that "the Soviet Union now has the responsibility for creating the conditions that would make it possible for everyone, and that includes the United States, [to] participate in the Moscow Olympics."

In his dispatch from Paris, Koven reported:

Giscard said it is important for Moscow to understand the limits it cannot overstep and that France had informed the Soviets what those limits are from the start of the crisis. "As long as those limits have not been overstepped," he said, "it is legitimate to seek the means and conditions that would permit a halt to the Soviet Intervention in Afghanistan.

The clear implication was that the intervention itself does not represent a Soviet step out of bounds for the French. Giscard said the Soviet ambassador in Paris would be called in to have the Franco-German text explained.

The six-point text said that Paris and Bonn consider the Soviet military intervention "unacceptable," that the crisis could lead "step by step" to "serious consequence for the world" and that both countries therefore reaffirm their loyalty to the Atlantic Alliance "and their determination to honor its commitments."

"Because of the events in Afghanistan," the declaration said, "detente has become more difficult and more uncertain and . . . consequently withdrawal of foreign troops from Afghanistan is necessary. They declare that detente would not survive another shock of the same kind. In that case, France and the German Federal Republic would, in coordination with their allies, take the measure that the circumstances call for to guarantee their security and to defend international stability."

The joint communique said Paris and Bonn understand the preoccupations of "the countries authentically attached to nonalignment." Extension of the East-West confrontation to the Third World must be avoided, the text said.

The European powers have "special responsibilities" to exercise in the present crisis, the communique issued in Paris said. The West Germans said this referred to Schmidt's idea that there should be a division of labor among the allies, with Bonn helping crisis-ridden Turkey economically and militarily and Pakistan economically, while France continues to help friendly governments in Africa.

In another move, France and West Germany agreed today to launch what Giscard said would be a $10 billion program to build a main European battle tank to replace both the French AMX 30 and the German Leopard. Giscard said the two nations would order 4,000 of the tanks and would also sell to others.

The French president referred to the German Leopard as the "Leopard I," seeming to confirm speculation that the new tank essentially would be an updated version of the current German tank. The Franco-German accord insures that there will be stiff competition with the United States to conquer world markets for the tank of the 1980s.