''This is the first threat that we are aware of for an American reporter,'' said Ann K. Cooper, executive director of the committee. She sent a letter Wednesday to Lewis D. Schiliro, director of the F.B.I.'s New York office, requesting a meeting to discuss what the Federal Government can do to protect Mr. Friedman.

''The Russian Mafia has learned that it can get away with violence and intimidation in Russia and now this seems to be a case where a Russian Mafia leader believes he can operate in the same fashion in this country,'' Ms. Cooper said. ''We are saying no, it shouldn't happen in Russia and it shouldn't happen in the United States.''

Ms. Cooper said yesterday the the F.B.I. had agreed to discuss Mr. Friedman's situation with her.

When the F.B.I. advised Mr. Friedman to ''lay low'' last June, he said it also advised him to keep quiet about the threats. After about eight months of doing what he was told, Mr. Friedman said he grew weary of cowering and became furious with the Federal Government's advice.

In a meeting last month with F.B.I. officials in New York, Mr. Friedman said he demanded that they take action against one of the Russian mobsters who has threatened him. He later decided to ''kick up his heels,'' ask for help from the Committee to Protect Journalists and talk to the press.

''I was a good soldier for a long time, but then I felt like a billy goat on a stake,'' Mr. Friedman said. ''I have been exposed too long and the people making these threats have gone unpunished too long.''

The F.B.I. declined comment on what it is doing to protect Mr. Friedman. Joe Valiquette, a spokesman for the bureau, sounded irritated over the telephone that the journalist had chosen to go public.

''Since Mr. Friedman has no reluctance, I will leave it to him to discuss the nature of his threat,'' Mr. Valiquette said. ''He is aware of what we know.''