The International Olympic Committee will send a delegation to meet formally with South African political and sports leaders in Johannesburg in April, a breakthrough that could open the Olympic Games as early as 1992, but more likely by 1994, to a nation isolated by the international sports community.

The IOC's policy has been that apartheid, a system of racial separation, must be abolished before South Africa is allowed back into the Games for the first time since 1960. Because South Africa President F.W. de Klerk recently has been moving his country toward racial unity, international sports officials have begun making contact with their counterparts there.

In the first day of its meetings in Lillehammer, Norway, site of the 1994 Winter Games, the IOC executive board -- which includes U.S. Olympic Committee President Robert Helmick -- voted in an unprecedented move to send the five-member delegation to South Africa.

This will be the first official contact between the IOC and South Africa since the country was expelled from the IOC in 1970 because of apartheid.

One member of the delegation, Judge Keba Mbaye of Senegal, chairman of the IOC's anti-apartheid commission, said there is a chance South Africa could participate in the 1992 Barcelona Summer Olympics, July 25-Aug. 9.

Mbaye was quoted by NTB, the Norwegian news agency, as holding open that possibility, but NRK, the Norwegian radio network, said it was more likely South Africa would return in time for the Lillehammer Games. It was not immediately certain what winter sports, if any, South Africa plays.

Other IOC officials, including President Juan Antonio Samaranch, have been quoted as saying the 1996 Summer Olympics in Atlanta would be the most likely time for South Africa's return. If that's so, it would be a significant, possibly even triumphant, re-entry of the shunned nation at the Games played deep in the American South. One of the reasons Atlanta won the Olympics in September was the strong influence former U.N. Ambassador Andrew Young had among the IOC's black African members.

Mbaye also told the Norwegian news agency that the IOC will maintain its policy of allowing the black African nations, a formidable bloc within the IOC, to make the final decision on South Africa's readmission to the committee.

"Whether South Africa would again be included in the Olympic family depends on the viewpoint of the other African nations," Mbaye said.

Earlier this year, the African Olympic group sent a delegation on a fact-finding mission to Johannesburg. The group also met in Harare with South African sports officials last month.

The IOC's official delegation will be composed of Mbaye; Kevan Gosper, an IOC vice president from Australia; Jean-Claude Ganga of the Congo, head of the Association of National Olympic Committees of Africa; Major General Henry Adefope of Nigeria; and Francois Carrard, the IOC's deputy general.

"It's obviously significant," said Mike Moran, USOC public information and media relations director. "I don't know that it will signal South Africa's return to the Olympics by 1992, but, to me, at first glance, it looks like a significant trip."

"It is significant for the IOC," Fekrou Kidane, a journalist and anti-apartheid activist who works as a consultant for the IOC on Third World issues, told the Associated Press. "They want to see what is what. They want the full view of the situation. . . . It is among the most dramatic developments."

Kidane said the delegation will meet with "the highest political and sports officials in South Africa. Whether we like it or not, there is no sports solution without a political solution in South Africa. So, by meeting with the various political parties, they will have a better idea of the situation."

The decision of the 10-member IOC executive board officially came in the form of acceptance of a proposal by its special commission on apartheid in sports.