By John M. Goshko
                  Washington Post Staff Writer
 
                  UNITED NATIONS, Dec. 23—The United States today ordered three
                  diplomats from Cuba's U.N. mission to leave the country because of
                  involvement with an alleged Cuban spy ring in the Miami area that was
                  broken up last September.

                  In ordering the expulsions, the White House and State Department said
                  only that the three had been involved in "activities incompatible with their
                  status as members of the U.N. mission." Sources familiar with the situation
                  said the three had ties -- apparently in relaying orders and acting as
                  paymasters and couriers -- to the 10 people arrested in southern Florida
                  on Sept. 13 on charges of spying on U.S. military installations and seeking
                  to infiltrate Cuban exile groups opposed to President Fidel Castro's
                  communist government.

                  "This action was taken as the result of evidence developed during an
                  exhaustive investigation by the FBI," State Department spokesman James
                  P. Rubin said.

                  The crackdown in Florida, involving eight men and two women, including
                  two married couples, was the largest roundup of alleged Cuban agents
                  since Castro came to power in 1959.

                  The diplomats being expelled are Eduardo Martinez Borbonet, a first
                  secretary; Roberto Azanza Paez, a third secretary, and Gonzalo Fernandez
                  Garay, an attache. U.N. officials said the U.S. government gave them until
                  Monday to be out of the country. U.S. officials said two other, unidentified
                  members of the Cuban U.N. delegation would have been expelled, but left
                  the United States weeks ago.

                  The chain of events began Monday evening when the United States
                  informed the Cuban mission and Secretary General Kofi Annan that it
                  intended to expel the three but would give Cuba 24 hours to respond to
                  the charges and argue why that should not be done. The sources said the
                  24-hour deadline passed without a response from the Cubans, and the
                  decision to go ahead with the expulsion was made by the White House and
                  State Department late Tuesday.

                  Neither the Cuban mission here nor the Foreign Ministry in Havana
                  commented on the expulsions. They bring to 12 the number of Cuban
                  diplomats at the United Nations ordered to leave since 1982.

                  Although the stated reason always has been for activities "incompatible"
                  with their U.N. duties, that is the common diplomatic euphemism for
                  espionage. The last expulsion here was in 1995, when three members of
                  the Cuban mission were ordered to leave after getting into a fight with
                  police and exile protesters at an anti-Castro rally.

                  Cuba expelled a U.S. diplomat from Havana in 1996 after charging her
                  with improper activities. The United States retaliated by expelling a
                  member of the Cuban interests section in Washington.

                  Since the United States and Cuba do not have formal diplomatic relations,
                  each country's diplomats in the other's capital work out of interest sections
                  that technically are a part of a third-country embassy. Cuba is allowed to
                  maintain a diplomatic mission at the United Nations under the world body's
                  headquarters agreement with the United States, although its diplomats here
                  are subject to restriction on their movements and activities.