French wine producers are taking the environmental group Greenpeace to court over an anti-nuclear campaign they say amounts to commercial blackmail.

The National Committee of AOC Wine and Liqueur Professionals says it has asked a Paris judge to stop Greenpeace from distributing a list of names of French companies that have declared their opposition to the country's ongoing nuclear testing program in the South Pacific. AOC or Appellation d'Origine Controlee is the French wine registration office. The case will be heard Sept. 28.At the center of the dispute is an advertisement published in the French press last month in which Greenpeace warned that as a last resort to stop the nuclear tests it would call for a consumer boycott of French products.

In the ad, Greenpeace called on all French companies opposed to the tests to come forward within a few days so the group could communicate their names abroad and help them avoid becoming targets of a boycott.

The environmental group warned that the boycott was gathering momentum and ''nobody can tell where (it) may lead. Only a speedy halt to the nuclear tests can put an end to this situation."

Greenpeace has not formally called for a boycott yet.

Jerome Agostini, director of the wine producers group, says the advertisement not only amounted to blackmail but it was an indirect call to consumers to boycott products made by French companies.

''This is intolerable in a civilized country," he said. "Companies have a right to stay out of politics and Greenpeace is trying to force them to take a stand."

But Penelope Komites of Greenpeace in Paris said the group is one of the rare organizations that hasn't called for a boycott because it believes the majority of French citizens are against the nuclear tests.

''I totally reject the accusations," she said, adding that the French wine producers should consider taking legal action against President Jacques Chirac for any financial losses they may have sustained.

Mr. Agostini said exporters of French wine registered at least a 20 percent decrease in sales in Sweden and Denmark during the months of July and August.

He said the drop was due to consumers snubbing French wines as well as exporters and distributors canceling orders either as a political statement or

because of worries that sales would weaken. French wine producers say any loss in market share will take years to recover.

''The prime minister of Denmark has made a series of declarations that he and his wife will not drink French wine until the nuclear tests stop," Mr. Agostini said. "What kind of Europe is this?"