THREE decades of Soviet-Cuban military cooperation appear to be drawing to a close, and the Soviets seem set to further revise close economic ties as well.In the wake of the failed hard-line coup, analysts say Soviet relations with Cuba - its longtime Cold-War ally parked 90 miles off the Florida coast - are shifting to a purely political and economic footing. The results of the Soviet action could loosen Cuban leader Fidal Castro's long hold on power. On Wednesday, President Mikhail Gorbachev announced the withdrawal of some of the 11,000 Soviet troops that he says are stationed on the Caribbean Island. His comments were also interpreted in some quarters as indicating that the roughly $2 billion Cuba receives in economic subsidies on Soviet oil would be eliminated in favor of a shift to a free-market relationship. "We intend to transform our relations with Cuba to a plane of mutually beneficial trade and economic ties, and we will remove other elements from that relationship that were born in a different time and a different era," Mr. Gorbachev said. The Bush administration in recent weeks has indicated the Soviet Union's ongoing relationship with Communist hold-out Fidel Castro is an impediment to US economic aid. US Secretary of State James Baker III, in Moscow on a five-day visit, praised the decision as a "positive step" and a "very substantial gesture." "This withdrawal is very important symbolically," says Gillian Gunn, a Cuba specialist with the Carnegie Endowment for International Peace. "The Cuban relationship is being redefined, and redefined very quickly." The troop pullout is seen as another sign of the ascendancy of Soviet reformists, embodied by Russian Federation President Boris Yeltsin, and an indication of mounting Soviet desperation for economic aid. The troop pullout also portends the end of an era of cooperation marked by the 1962 Cuban missile crisis and Cuban involvement in Angola and Ethiopia. The reaction from Cuba was unusually swift and angry. In a statement, the Cuban Ministry of Foreign Affairs blasted the lack of prior consultation as "inappropriate behavior." It complained about the failure of Gorbachev to speak out about the "illegal occupation" of Guantanamo Bay, which the US rents for a naval base. And in an unusual public correction, the ministry said the "essentially symbolic" Soviet troop total in Cuba was wrong. "Gorbachev has used Cuba as a bargaining chip with Baker," says Ms. Gunn. If he's annoyed enough, Castro may kick the Soviet troops out [before the withdrawal] to preserve pride and dignity." If so, would Mr. Castro boot out the estimated 2,100 Soviet signals intelligence technicians running Lourdes, one of the largest Soviet electronic eavesdropping facilities? US analysts say the sophisticated equipment is largely off-limits to Cubans and may be of little initial value. But Cuba might be able to rent the listening post to China, or the highest bidder, for hard currency. Although the military strategic value of the Lourdes facility to the Soviets is arguably diminishing, they have shown no signs of wanting to abandon it. Indeed, Soviet republics embracing free enterprise may find it of growing value. One Western expert on Soviet signals intelligence says Soviet electronic surveillance centers worldwide are increasingly used for industrial espionage. "Castro can't afford to burn any bridges," says Jose Cardenas, director of research for the Cuban American National Foundation, a Miami-based conservative lobby group. Mr. Cardenas says that Cuba's economic problems are so bad that Castro cannot afford to risk severing what ties remain to the Soviet Union with a vitriolic response to the troop withdrawal. But he predicts Castro must respond to the "devastating psychological impact on the Cuban people of the Soviets packing up and leaving them." It increases the likelihood of economic and minor political reforms being announced at the Fourth Party Congress next month, Cardenas says. "I don't see how Castro can go to the Congress without offering some semblance of hope."