West Germany's highly successful Stern magazine, which has a fondness for putting bare-breasted women on its cover, may have gone too far this week. The mistake was a costly one.

A million copies of the magazine were published with a cover that had a lifelike and extraordinarily eye-catching drawing of a man and a woman, wearing provocative undergarments, engaged in a sex act on chair. It illustrated a picture story about the notorious Sankt Pauli section of Hamburg, where live sex shows and just about anything else can be seen and bought.

The magazine's editor-in-chief, apparently horrified or perhaps sensing a certain lack of good taste, stopped the presses and ordered a new cover printed for the rest of weekly press run - about 800,00 more magazines.

The new cover - on magazines delivered to the northern part of the country - showed two woman dancers in a Hamburg sex show in the topless attire common on German magazine covers.

The first million or so copies were distributed in the usual way, however. Throughout southern and central West Germany, shoppers in supermarkets, patients in doctor's waiting rooms and families checking the morning mail have been gawking at the cover drawing. Many women, already bombarded by the weekly topless poses in so-called family magazines, were outraged by the latest assault.

"It is disgusting and ridiculous. Stern always tried for extremes but they have really crossed the line on this issue," said Elizabeth Noelle-Neumann, who runs West Germany's best known public opinion survey, the Allensbach Institute.

Alice Schwarzer, editor of a rapidly-growing feminist monthly magazine called Emma, said staff members are planning to sue Stern.

"We are all revolted, especially because Stern is a political magazine. We have watched the cover pictures of magazines become extremely sexual in the past few years and now they have really gone too far," she said.

What the cover says about West German society, she added "is that it is very much still a man's society and that women don't fight enough against discrimination in general and especially against this kind of discrimination and degradation."

The publisher of Stern, which claims a readership of about 8 million weekly and which Noelle-Neumann estimates goes into about every third household, said the magazine has received many complaints from people "who say it was disgusting or ask, why do you do such a thing."

"Nevertheless," publisher Peter Hess said, "people are buying it. I don't really care about those voices expressing disgust or that it is bad for Stern, because it was only a cover and the story was quite good."

Still, he adds, "I'm happy I didn't have to make the decision" on which cover to use. Hess said that despite the controversial nature of the cover, the decision was made by a deputy editor while Editor-in-chief Henri Nannen was away. Nannen, who stopped the presses on returning from the trip, was not available for comment yesterday.

Stern is not alone is reflecting a West German fondness for displaying women's bodies on the covers of family style magazines.