While merchandisers gleefully applaud a recent federal appeals court decision barring the sale of unlicensed Boston Marathon T-shirts, others believe the ruling goes too far in expanding trademark rights.

"It's the most significant opinion in the field of merchandising I've ever seen," said Washington trademark lawyer Stephen Trattner, referring to the ruling by the 1st U.S. Circuilt Court of Appeals that barred an entrepreneur from selling Boston Marathon goods not licensed by the Boston Athletic Association, which has sponsored the famed road race since 1897."It will greatly benefit rock groups, movie producers, sporting events and any kind of entertainment where souvenirs are sold," said Trattner, who represents the U.S. Golf Association in its battle against unauthorized goods.

But the ruling is described by some lawyers as "extremely troubling," so broad it could conceivably ban the sale of items even remotely associated with a known event or product.

The January ruling encompassed not only items bearing the words "Boston Marathon," but other goods with no direct reference to the marathon, including T-shirts decorated with the words "Boston-1988" and carrying the picture of a runner.

The appeals court said Mark Sullivan of Hopkinton, Mass., the loser in the case, sought "a free ride at (the BAA's) expense."

"Suppose you were a vendor outside Fenway Park. Does this ruling mean the Red Sox could stop the sale of pennants saying, `Go Boston' and nothing more? I'm not so sure," said Boston trademark lawyer David Wolf of the firm Wolf, Greenfield & Sacks.

Most significantly, the appeals court expanded traditional trademark law by granting broad protection of an event itself, without requiring a showing of consumer confusion over an associated product's origin.

"The court broke new ground by saying that when you have a well-known event like the Boston Marathon, and someone trades on that, it's an infringement of the good will of the event," Trattner said.

"The court focused on the triggering mechanism of why someone buys a product, which is because they want a souvenir of the event," said the USGA lawyer. "You now no longer have to prove whether the person was confused as to who made or licensed the T-shirt, hat or whatever."

The USGA filed a friend-of-the-court brief in the Boston Marathon case, after it was initially denied an injunction to stop sales of unauthorized souvenirs when the U.S. Open was held last June in Brookline, Mass.

"The ruling is a very real expansion of trademark law, in some cases unwarranted," said Wolf.

"It may affect many, many small companies that are legitimately selling products," he said. "We took a straw vote in our firm and most lawyers thought the decision was extremely troubling."

Not troubled at all by the ruling are professional sports teams and leagues, whose lucrative licensing deals are threatened by unuthorized goods displaying team logos.

"We're very aggressive in protecting our legal trademarks and this ruling is clearly going to increase that protection," said Steve Flatow, director of marketing for the National Hockey League.

Lawyers said the ruling will greatly reduce the cost of bringing trademark infringement cases, and should help speed up the granting of preliminary injunctions against alleged counterfeiters.

"It's no good to get a ruling four years later against these gypsies," said Boston lawyer John T. Williams.

Sullivan said he will not appeal the decision to the U.S. Supreme Court due to the expense involved. Most trademark cases never even reach the appeals court level for the same reason.

"There's a morality level" to the marathon ruling, said Harvard Law School Professor Arthur Miller, "an element of reaping where one has not sown, of piggybacking."

"But if one looks through American economic history you're going to find an awful lot of piggybacking," he said. "One of the things that made this country great is that we've developed new products, new ideas, based on old ideas.

"And when a court protects words like `Marathon' and `Super Bowl,' if it goes on much more some folks will have a large piece of the English language and the rest of us aren't going to be left with much."