After seven weeks of labor unrest in a neighboring communist country, the Soviet Union has yet to take public notice of what appears to be developing into a challenge to Poland's government.

The silence suggests that Moscow has cast its lot with Polish leader Edward Gierek -- at least for the time being -- in hopes that his government can resolve the crisis through negotiations and conciliatory measures.

The soviets are believed to be avoiding mention of the Polish events for fear that any statement could be construed as outside interference. Indeed, their restraint seems designed to provide Gierek with time to restore industrial peace.

Diplomats here believe that this policy is aimed at containing possible repercussions throughout Eastern Europe as well as preventing a collapse of detente with Western Europe that Soviet intervention would produce.

Since the sharp deterioration in U.S.-Soviet relations, Western Europe has become a major focus of Soviet foreign policy. The Russians have assiduously courted West Germany and France, in particular, in efforts to exploit difference within NATO.

Despite Carter administration efforts to create a joint allied front against the Soviet Union after the Afghanistan invasion, the Soviets have managed to maintain a degree of East-West cooperation in Europe. Soviet President Leonid Brezhnev had met French President Valery Giscard d'Estaing in Poland last May and West German Chancellor Helmut Schmidt was accorded an unusually warm welcome when he visited here in June.

Diplomatic sources here say the Soviets do not want to be pushed into military intervention because that could lead to a renewal of the cold war in Europe.

Such a move would virtually cancel all Soviet efforts during the past six months to persuade the West Europeans to delay the scheduled deployment of U.S. medium-range nuclear missiles in 1983, a key objective of Soviet policy.

Moreover, Moscow is believed to see its interests as parallel to those of several Western European governments -- and banks with large exposure in Poland -- that have indicated willingness to help Gierek out of the current predicament. Indeed, Gierek's trip to West Germany, now postponed, was part of a Polish drive to obtain new credits and renegotiate old ones.

Gierek has been viewed in Western Europe as a flexible and pragmatic partner who sought to contain the erosion in East-West relations after Afghanistan. A successor could turn out to be more difficult.

However, the mushrooming unrest in Poland seems to have a momentum of its own and is closely watched from here. Most of the workers' demands have gone beyond what Moscow would be likely to find acceptable since they challenge the communist government politically.

Gierek, who was vacationing in the Soviet Union for two weeks until Friday, is believed to have discussed such issues with his Soviet hosts. Gierek, in his speech tonight, rejected demands for sweeping reforms of the system, saying Poland can be independent only under socialism.