U.S. USING CUBA LAW TO PUNISH CANADIANS.

Byline: David E. Sanger The New York Times

The Clinton administration struck for the first time Wednesday against foreign companies operating in Cuba, informing the top executives and shareholders of a large Canadian mining concern that they and their families will be barred from entering the United States, State Department officials said.

The action against Sherritt International Corp. was the first application of the Helms-Burton law, which President Clinton, against the advice of many of his closest advisers, signed this year. It has raised a storm of protest throughout Europe and Latin America, and Canada has told its companies to ignore American threats and warned it may retaliate with countersanctions.

American officials said that executives from telephone companies in Mexico and Italy will be informed in coming days that they will also be barred from visiting the United States and from sending their children to visit or study here.

While Wednesday's action seemed to represent a hardened line by the administration, behind the scenes the White House is debating whether to bow to the protests abroad by suspending enforcement of another provision of the law that could cost foreign companies hundreds of millions of dollars.

Clinton faces a Monday deadline to decide whether to allow American companies whose properties in Cuba were seized by the government of President Fidel Castro to file suits in U.S. courts against foreign companies that are now using them.

The State Department spokesman, Nicholas Burns, said Wednesday that ``there is a good deal of discussion about that issue'' and that no decision had been made.

The issue is fraught with election-year risks. Clinton signed the Republican-sponsored sanctions bill reluctantly in February after Cuban warplanes shot down two small civilian planes flown by an anti-Castro group based in Florida.

The economic isolation of Castro is an enormously charged issue within the Cuban-American community in Florida, an important state in the November presidential election, and political advisers of Clinton are urging him to take a hard line against companies doing business with Cuba.

But a hard line could also hurt Florida's economy. A coalition of Canadian church, labor and relief groups urged Canadian tourists Wednesday to boycott the state unless the United States relents on Helms-Burton. About 2 million Canadians travel to Florida each winter, spending about $1.3 billion.

Clinton's economic advisers, including Treasury Secretary Robert Rubin and the chairman of the National Economic Council, Laura D'Andrea Tyson, have made it clear that they are worried about retaliation against American companies.