UPDATE : It’s No Life of Leisure for Gorbachev : He’s apparently determined to remain a key player on the global political scene. And visitors are making his think tank a ‘must’ stop.

There is no name on the big, sand-colored building, just an address--Leningradsky Prospekt 49--but diplomats, historians, political scientists and statesmen from around the world are making it a “must” stop in Moscow.

Formerly the Soviet Communist Party’s Institute of Social Sciences, No. 49 houses the International Foundation for Social, Economic and Political Research, better known as the Gorbachev Fund.

When he resigned as president of the Soviet Union in December, Mikhail S. Gorbachev was determined to remain on the international scene, promoting around the world the ideas that brought such vast changes to his own country. The foundation has become his operating base.

“Gorbachev intends to remain engaged, both here and abroad, because there is a lot still to be done, a lot that he wants to do,” said Vladlen Loginov, the foundation’s spokesman. “He is profoundly convinced that many ideas of perestroika must be incorporated in the directions the world takes into the 21st Century. . . .

“The Gorbachev Fund will be a center not only of research, but of active involvement in major political developments. Gorbachev intends to speak out, to travel, to consult with world leaders. He hopes, for example, that this foundation will train a new generation of politicians for our country and help promote Russia’s democratization.”

Each day about noon, Gorbachev’s black, armored Zil limousine rolls in from his home outside Moscow, and a short time later, the procession of visitors to the former president’s second-floor office begins. Former Secretary of State Henry A. Kissinger was Gorbachev’s very first visitor last month.

“His days are very intensive--he has an extraordinary level of energy,” Loginov said of Gorbachev, who will be 61 next month. “It is not just that the hours are long--he works through to 9 or 10 p.m. each day--but the ideas, the projects, the plans just pour forth.”

Sen. Alan Cranston (D-Calif.) said after meeting Gorbachev this week that former President Jimmy Carter, with his efforts in international mediation, appears likely to become something of a model for Gorbachev.

“Gorbachev sees an opportunity to use his knowledge and talents for further change and to remain a force for progress as the new world order develops,” Cranston said. “He is the most respected person on Earth--except in his own country, unfortunately, and probably in China--and that gives him terrific authority. . . .

“Instead of a think tank, I think he will make the Gorbachev Fund an ‘action tank.’ ”

Loginov, a tweedy historian who worked at the old Institute of Social Sciences for 10 years, said that Gorbachev wants to combine path-breaking research and theoretical work with a more active role for himself.

“When he speaks, he wants to make sure that what he has to say has weight, real body, that it has been thought out and substantiated,” Loginov said.

Six study groups have been established under the direction of foundation Vice President Alexander N. Yakovlev, the political scientist who was the architect of much of perestroika.

The group studying global problems is headed by Georgy Shakhnazarov, a close Gorbachev adviser; the one on political theory by Alexander Tsipko, an iconoclastic philosopher whose bold break with Marxism took much of the Communist Party leadership with him, and that on forecasting by Alexei Salmin, regarded as one of the country’s most brilliant sociologists.

Groups for economic, sociological and scientific studies are also being formed, as well as a council of independent senior advisers. “So many chiefs for so little space,” a foundation staffer said, shaking his head over the influx at the institute, which once was a school for training Communist Party officials.

Grigory I. Revenko, who served as Gorbachev’s last Kremlin chief of staff, is the foundation’s other vice president, and his focus will be Gorbachev’s public activities, including forthcoming lecture tours and fund-raising trips to Western Europe, the United States and Japan.

Gorbachev has also brought with him other advisers from the Kremlin and party headquarters, and more are likely to come as they fail to find jobs in Boris N. Yeltsin’s new Russian government. Altogether, the foundation is expected to have more than 100 professional staff members and 500 support personnel.

“A person with 30 years’ experience in the old system may have trouble fitting in today, no matter how brilliant he is,” said Yuri Krasin, the head of the sociological studies center and former rector of the institute. “There could be a lot of talent wasted. . . . We are not offering a refuge, but a chance to participate in the formation of this new society.”

One use for these talents is the informal “Gorbachev University” that is beginning to train young activists from a variety of democratic parties in practical politics--how to organize a party from the grass roots, write a platform, select candidates and campaign for election.

The foundation is also retraining high school history and social science teachers in weeklong courses aimed at overcoming years of Marxist-Leninist indoctrination.

Funds are coming primarily from Gorbachev’s earnings abroad--a new book on the collapse of the Soviet Union due out in a month, fees for lengthy interviews with U.S., European and Japanese television companies and the planned lecture tours. The foundation also inherited a 160-room hotel and other revenue-producing facilities.

“The amounts of money we are looking at are very impressive,” Loginov said of Gorbachev’s projected foreign earnings. “The revenues are quite handsome. Gorbachev will have enough of what he needs to carry on what he began seven years ago.”