Moscow — Soviet officials are deeply worried over the expected ouster of West German Chancellor Helmut Schmidt by a center-right coalition.
The Soviets fear that, in the short run at least, the shift in Bonn will complicate relations with NATO's most powerful European member state and make the deployment of new US missiles in Western Europe, set to begin late next year , more likely.
To the extent that Moscow sees a possible silver lining in Chancellor Schmidt's expected removal, a Soviet analyst says privately, it is that a new, conservative coalition might give added impetus to popular pressure against the planned missile deployment.
''If so,'' he says, ''it is conceivable that this could have an important political effect, both within West Germany and in Europe generally.''
The current feeling among Soviet officials, however, seems one of deep concern.
This concern has been made clear in remarks to European diplomats here, and to various Western visitors. One recent visitor was told by a senior Soviet official that he was particularly worried over two recent world developments, the violence in the Mideast and the political crisis in West Germany.
Moscow has long viewed its relations with Chancellor Schmidt - and with his predecessor and party colleague, Willy Brandt - as central to overall East-West detente.
Particularly as Soviet-American relations have worsened in the past several years, Moscow has come to see Mr. Schmidt's West Germany as a potential counterweight to American policy within the Western alliance.
Moreover, another West European leader viewed in analogous fashion here - former French President Valery Giscard d'Estaing - was replaced in May of last year by Socialist President Francois Mitterrand, initially far frostier toward the Kremlin.
With the recent resumption of formal policy-review consultations between Soviet and French officials, relations with the French government have thawed incrementally, although they are still nowhere near as smooth as under President Giscard d'Estaing.
If the West German Parliament does follow through Oct. 1 with moves to replace Chancellor Schmidt, diplomats here expect a serious Soviet effort to establish a workable relationship with his successor while pushing for a further revival of Giscard-era ties with Paris.
At first, the Soviet moves are expected to be largely atmospheric. But some diplomats think it is likely that the Kremlin will eventually soften its negotiating stand on limiting nuclear forces in Europe in hopes of a general improvement in relations with Western Europe, and of renewed European pressure against the deployment of additional US missiles.
Under Chancellor Schmidt, Moscow has clearly been assuming, such ''pressure'' against deployment within leftist circles of his party was likely to increase as the planned deployment date drew nearer.
Mr. Schmidt's expected successor, Christian Democrat Party leader Helmut Kohl , is likely to feel much less strain within his ruling coalition - although, as the Soviet analyst quoted above suggests, time will tell whether this development may be balanced by increased popular pressure.
In a Schmidt-era assessment of Mr. Kohl, and of allied Christian Social Union leader Franz Josef Strauss, an article in the Soviet journal International Affairs said the two leaders represented an ''obstructionist stand in foreign policy.''
The article, appearing in July 1982, portrayed the conservative allies as seeking to ride ''anticommunist hysteria'' into power.
''Washington is openly flirting with . . . Helmut Kohl and (Franz) Josef Strauss, making no secret of the fact its sympathies are on their side,'' the article said, concluding: ''West Germany is going through a complicated and tense phase . . . once again at the crossroads, and its choice will have a decisive effect not only on its future, but also on tranquillity, stability, and peace in Europe.''