The firing of Felix Bloch, who is alleged to have had secret ties with Soviet spies while serving as a high-ranking diplomat, represents the first time the United States has dismissed a State Department official for national security reasons.

Bloch, 55, a former chief of mission at the U.S. Embassy in Vienna, was fired Monday by Secretary of State James Baker. The decision followed a hearing and review by an internal board of appeals.In using the obscure national security provision, Baker found Bloch's removal "necessary and advisable in the interest of national security because of his deliberate, false statements to the FBI in the course of a national security investigation."

The dismissal order also cited Bloch's "behavior, activities and associations," but those allegations were not specified.

No formal charges have been filed in the case.

Bloch did not issue a statement on his dismissal.

Leaks from U.S. government investigators said Bloch had been in contact with a Soviet agent in Paris and in Vienna and that he had been photographed handing over a briefcase to the Soviet citizen.

According to leaks, Bloch was taped-recorded telling his wife that he had received money from the Soviets, but the surreptitious recording would not have been admissible in a U.S. court.

The State Department and the FBI have never revealed what information Bloch is accused of surrendering to the Soviets. As a high-ranking official in the Vienna Embassy, he would have had access to top secret documents, including arms control negotiating position papers.

He also would have been aware of the names of any intelligence agents working under cover in the U.S. Embassy.

Bloch was suspended from his $80,000-a-year job when the investigation began last year. He remained on the payroll until earlier this year when the national security charges surfaced.

His dismissal was effective immediately. His pension, which would eventually be more than $50,000 a year, is not directly affected by the firing.

While he was suspended and under investigation, he was followed by teams of FBI agents and television camera crews throughout Washington. Periodically, without exchanging any words with them, he would lead them on "death marches," rapid-paced hikes that would be as long as 22 miles.

Bloch was born in Austria and had served in Berlin and Vienna as a political and economics officer. In Vienna, he had served under two Reagan administration political appointees, Helene Von Damme and Ronald Lauder, both widely regarded as inexperienced amateurs.

Bloch had occasionally expressed his scorn for them and his frustration of being passed over for higher posts by such political appointees in talks with other diplomats.

He would have been in line for an ambassador's post, but the Reagan administration filled the available spots with political appointees, and Bloch was sidelined to a minor office in the State Department, which kept track of the activities of the European Common Market.