Kohl's center-right coalition is shaken by Lambsdorff crisis

The expected indictment of West German Economics Minister Otto Lambs-dorff for bribery in the ''Flick affair'' knocks the center-right coalition of Chancellor Helmut Kohl for a loop.

It greatly increases the pressure of the irrepressible Franz Josef Strauss for a Cabinet post. It will test to the limits Dr. Kohl's adroitness at using the Free Democrats - the smallest party in his coalition - to balance off the Bavarian powerhouse, Strauss.

Depending on how far things go, this ''Bonn Watergate,'' as it is being called, might also rock the cozy industry-party relationship in which the country's establishment firms help fund establishment parties, and the accounting rules are left rather vague.

So far Free Democrat Lambsdorff is not resigning. And Kohl is conspicuously not pushing him to do so. Both men are proceeding from the precept that a person is innocent until proven guilty - a point also stressed by federal prosecutors Tuesday in announcing their request that Lambsdorff's parliamentary immunity be lifted so he may be indicted.

The opposition Social Democrats and Greens are already calling for his resignation, however, and the pundits are arguing that it will be politically impossible for Kohl to keep in his Cabinet the first sitting minister to be indicted in West German history.

No one is more convinced of this verity than Strauss's Christian Social Union allies. For a few weeks - as the day of the Flick indictments approached - they have been dropping broad hints that Strauss might like to leave the Bavarian premiership and take over an enhanced Economics Ministry in Bonn.

Kohl is resisting this elbowing by his longtime rival for conservative leadership. ''That's the Free Democrats' post,'' notes a Kohl aide in explaining why he doesn't expect Strauss to take over the Economics Ministry. ''Otherwise the chancellor has to open the whole package (of Cabinet distribution) again.''

In this existing distribution Kohl's Christian Democrats hold the finance, defense, labor, and various other portfolios; the Free Democrats lead the foreign, economics, and justice ministries; and Strauss's Christian Social Union has the interior, agriculture, building, transportations, and foreign aid ministries. This corresponds to the Christian Democrats' 38.2 percent of the vote in last March's election, the Christian Social Union's 10.6 percent, and the Free Democrats' 6.9 percent.

The problem for Kohl is that the Free Democrats have no one readily available to fill Lambsdorff's post if he resigns. Besides, Kohl is reluctant to dump the man who was instrumental in bringing him to power a year ago by getting the Free Democrats to jump from a coalition with the Social Democrats to a coalition with the conservatives.

The obverse of this is that Lambsdorff is intensely disliked by the Greens and many young Germans and seen as the personification of West Germany's old-boy party-industry network.

The suspicion about Lambsdorff raised by the prosecutors after almost two years of preliminary investigation is that he knowingly took cash bribes worth 135,000 marks (roughly $365,000) between 1977 and 1980 as payment to his party for favorable tax treatment for the Flick concern. The Flick holding company paid minimal taxes on some 1.9 billion marks worth of Daimler-Benz stocks it sold back in 1975.