LAUSANNE, SWITZERLAND, SEPT. 17 -- Juan Antonio Samaranch, president of the International Olympic Committee, said today that members of the Soviet bloc would participate in the 1988 Summer Olympics in Seoul, South Korea, even if communist North Korea boycotts the Games.

North Korea still has not responded to a July IOC proposal that would allow it to host five sports, and Samaranch suggested the dispute might extend into 1988. But a boycott by North Korea would have little impact if the Soviet Union and its allies show up.

Samaranch said at a news conference that the Soviet Union recently had sent a delegation to Seoul as part of its preparations for the Games. Other IOC sources privately said the committee had received "assurances" from members of the the Soviet bloc that they would participate.

"The position, not only of the Soviet Union but also of all the socialist countries in Europe, is no problem. They are taking part in the Games," Samaranch said.

Samaranch previously had expressed optimism that a boycott by North Korea would not trigger a wider one, but he had not said specifically that the Soviet bloc would participate. The Soviets and most of their European allies boycotted the 1984 Los Angeles Summer Games.

Samaranch spoke after the IOC sent official invitations today to the Seoul Games to 167 national Olympic organizing committees. The IOC took that step despite a last-minute appeal by North Korea to postpone it.

Samaranch said he expects to meet Soviet leader Mikhail Gorbachev in the near future, and that he might ask Gorbachev to help persuade the North Koreans to reach an agreement with the IOC.

Samaranch will fly to the Soviet Union Saturday to attend a meeting of Eastern bloc sports ministers, and North Korean officials will be there. He might see Gorbachev on that trip, IOC spokeswoman Michele Verdier said.

The only new twist in the negotiations with North Korea is an IOC suggestion that Pyongyang might host women's basketball instead of the currently proposed women's volleyball, Verdier said.

Samaranch said the IOC already had offered North Korea "the maximum" number of sports that it could host. But he left open the possibility that some sports might be substituted for those already proposed.

Under an IOC proposal made July 15, North Korea would host archery and table tennis -- both men's and women's competition in those sports -- plus women's volleyball, the 100-kilometer cycling race and four first-round soccer matches.

North Korea is seeking to host all of soccer and has indicated that it wants to host at least one other team sport, as well, Verdier said. The North Koreans also have indicated that they want to be named co-hosts of the Games, but the IOC is backing up Seoul in ruling that out.

North Korea might be allowed to hold its own opening and closing ceremonies for sports that it hosts, according to IOC and South Korean officials.

Samaranch said there would be no further talks with North Korea until it accepted the July 15 proposal "in principle."

His strategy seems clear: to force North Korea to agree to participate in the Games in exchange for the prospect of a somewhat better deal on the sports it would host.

Samaranch, who had hoped to resolve the dispute by today, appears now to be willing to wait until early 1988. A factor in his newfound patience may be his conviction that he is not facing a major communist bloc boycott.

"We still have the door open for talks with North Korea and South Korea if North Korea accepts in principle the proposal of the IOC of July 15," Samaranch said.

He said he would not hold a planned IOC-North Korea meeting Oct. 7 if North Korea has not responded positively by then to the July offer.

Samaranch released the text of a letter he sent to Yu Sun Kim, president of North Korea's Olympic committee, saying the IOC is willing to continue seeking an agreement "until the last moment."

Asked when that "last moment" might be, Samaranch said "maybe" it would be "in the beginning of 1988." National committees have until Jan. 17 to accept invitations to participate in the Games.

"We don't know if they'll {the North Koreans} participate in the end. I think we'll have to wait until next year to find out," said an IOC source, who requested anonymity.

On a separate issue, Samaranch said U.S. cities' chances of winning the right to host future Olympics would not be affected by a recent U.S. decision to deny a visa to a Chilean marksman who had been scheduled to participate in the Pan American Games.

Samaranch had been quoted previously as saying that the visa decision would hurt the prospects of U.S. cities. Anchorage is seeking to host the 1994 Winter Olympics.