MOSCOW, AUG. 28 -- An October meeting between Soviet leader Mikhail Gorbachev and President Reagan in the United States is "still an active option," but no concrete plans for it have been made yet, a Soviet official, who asked that he not be named, said today.

Soviet Foreign Ministry spokesman Gennadi Gerasimov also told reporters today that a summit could take place in October if Soviet and U.S. diplomats make progress on an arms control treaty that could be signed at such a meeting.

Asked about a Washington Post report that Gorbachev has set aside time in late October or late November for the summit, Gerasimov said no specific time has been allocated for the meeting. Discussing summit dates would be premature, Gerasimov said. He said Gorbachev had other plans for late October.

Gerasimov's comments were consistent with the public position that he and other Soviet officials have taken in recent weeks when asked about the summit. They have consistently denied that concrete plans are being made for a meeting with Reagan or other Gorbachev appearances in the United States.

Soviet diplomats also have refrained from responding directly to Reagan's invitation to Gorbachev to visit the United States and from discussing details of the trip, according to U.S. and Soviet officials here.

Privately, however, Soviet officials have told some diplomats that a summit could take place in either late October or late November and that Gorbachev's schedule could accommodate such a meeting. They also asked United Nations officials about the possibilities of a speech by Gorbachev before the General Assembly in New York in late October.

Public discussion of summit dates would weaken the Soviet stance in negotiations to dismantle all U.S. and Soviet intermediate-range missiles, Moscow-based western diplomats said today.

One of several issue still under discussion in the negotiations is the verification procedure that will be used.

During the negotiations, the "Soviets would not want to give away their strongest card -- the right to back out of any agreement until it is completed," one western diplomat said.