Harvard Professor of Law Alan M. Dershowitz, who argued Claus von Bulow's successful appeal against a 1982 attempted murder conviction, said yesterday that he would continue to advise von Bulow's defense, but would not represent the case should a new trial be called.

Dershowitz said that he would be unable to represent von Bulow in trial because the proceedings are lengthier than those of an appeals court.

"A trial lawyer would miss classes, and I don't miss classes," he said, adding that in his 20 years as an instructor he had not cancelled a lecture.

A Wall Street Journal editorial editorial page article last month criticized Dershowitz for pursuing this professional law practice at the expense of his academic duties. Dershowitz yesterday denied this charge, nothing that he had spent only six of seven hours in trial so far this year. "I'm a law professor first and my law teaching comes first," he said.

Referring to the 20 percent limit placed on the amount of work a Law School professor may perform outside of the school. Dershowitz said. "I haven't even come close to it."

Dershowitz's appeal resulted in the reversal of von Bulow's conviction on the grounds that prosecutors examined crucial evidence without a warrant, and that during the 1982 that the presiding judge illegally barred the defense from certain information collected by the prosecution.

Legal experts have said that Dershowitz's appeal of the von Bulow case has broadened the scope of the exclusionary rule, which prohibits presentation in court of improperly obtained evidence.