A man who allegedly infiltrated the Central Intelligence Agency as an agent of the Czechoslovakian Intelligence Service (CIS) funneled the identities of American spies to Czechoslovakia for at least three years, a federal official said today.

Karl F. Koecher, 50, was charged with espionage, but a bail hearing was postponed until Thursday at the request of his lawyer, Joseph Calluori.

U.S. Attorney Rudolph W. Giuliani would not describe the seriousness of the intelligence leak, and the CIA has refused to comment on the case.

But Giuliani told a news conference that "virtually every piece of information that came into his Koecher's possession was turned over" to Czechoslovakian intelligence.

The complaint alleges that Koecher turned over the identities of "those individuals who worked for the CIA" with him between 1973 and 1975, when he was a CIA translator in Washington. Koecher also worked for the CIA in New York between 1975 and 1977.

Authorities said Koecher spied for the eastern-bloc nation for 19 years.

Koecher was arrested Tuesday night as he and his wife, Hana, were preparing to fly to Switzerland and begin a new life in Austria, the FBI said.

They had sold their $250,000 Manhattan home the day before. Hana Koecher, 40, was held as a material witness. Both are naturalized U.S. citizens.

Giuliani confirmed that Koecher has a doctorate in philosophy from Columbia University and said the couple recently worked "to some extent" at the Novissa Corp. jewelry firm in New York's diamond district.

Hana Koecher told authorities that she had worked for Harry Winston's jewelry house.

Giuliani, who said the FBI investigation began more than two years ago, declined to say what led to the couple's apprehension, what Koecher did after he left the CIA in 1977 or whether Koecher was trying to run out on a deal with the FBI when he was arrested.

An acquaintance in New York, Jay Rachmani, said Koecher said he quit the CIA " 'because the fair-haired boys were getting all the good jobs and we foreigners and strange-looking people were getting the dirty work.' "