Rep. William H. Gray III (D-Pa.), author and chief sponsor of antiapartheid legislation in the House, said yesterday he is waiting for events in South Africa to trigger future congressional efforts against the Pretoria government.

After chairing a hearing on "South Africa -- Where Do We Go From Here?" as part of the 15th annual Congressional Black Caucus weekend, Gray said that neither he nor other congressional opponents of apartheid are preparing new strategies to force stronger U.S. sanctions against South Africa.

Legislation that would have invoked sanctions against South Africa came to a halt in the Senate after President Reagan signed an executive order calling for more limited sanctions.

"Events will dictate what happens next," Gray said, "events that are beyond the Congress' control and beyond the president. The senators and the Congress will see if there is any movement away from apartheid in South Africa . . . . Remember that in the Congress there is bipartisan support for something stronger than what the president did."

Gray was joined at the hearing by Assistant Secretary of State Chester Crocker, chief architect of the administration's policy of "constructive engagement," Sen. Nancy Landon Kassebaum (R-Kan.), Rep. Howard E. Wolpe (D-Mich.), Pallo Jordan of the African National Congress, the leading antiapartheid group in South Africa, and Coretta Scott King, widow of slain civil rights leader Martin Luther King Jr.

Crocker defended the continuing use of constructive engagement as a tool that offers the United States diplomatic leverage in the effort to end apartheid.

Wolpe called for the United States to place more pressure on South Africa than the sanctions invoked by the president. Kassebaum warned that further disinvestment by Americans in companies in South Africa would hurt the antiapartheid movement, noting that the business community in South Africa actively is working to end apartheid.

But Jordan said there is a growing perception among black South Africans that the U.S. government supports apartheid, while King said "black America does not understand yet that you cannot get all you want when you want it." She urged adherence to nonviolence in seeking an end to apartheid.

It was Gray, however, who captured the audience with a soliloquy on why American politicians have failed to take stronger measures to oppose apartheid.

"People forget that we are only 20 years away from that kind of situation in our own country," Gray said. "It took us 200, 300 years to eradicate apartheid here by law. People forget that only 20 years ago, when I came here to Washington, D.C., as a boy, I couldn't go into the downtown hotels.

"They forget that Bill Dawson was the chairman of a congressional committee, that he and Adam Clayton Powell . . . couldn't eat in congressional members' dining room."

"We are only 20 years away from our own story, and that plays a part in our double standard [on South Africa]," he concluded.