SOWETO, SOUTH AFRICA, JAN. 14 -- The United States has made its first major grant to fight AIDS in South Africa, providing $242,000 to a center in this black township of 2 million people to support an information and prevention campaign.

The agreement, the subject of internal U.S. Embassy controversy, was signed at a Soweto ceremony Sunday with Secretary of Health Louis M. Sullivan and Agency for International Development Administrator Ronald Roskens.

The United States has become a financial mainstay of the worldwide campaign against AIDS, with Congress appropriating $52 million for this fiscal year, of which $11 million to $12 million is to be spent in Africa.

But Congress has been highly critical of the development agency's efforts so far to fight the epidemic in Africa, and the Senate Appropriations Committee has directed it to make available $2 million this fiscal year for a new program in South Africa.

According to several sources, development agency officials in Pretoria have been reluctant to spend money on the anti-AIDS campaign here because of difficulties expected to be encountered in administering it, particularly finding local groups capable of using the money effectively.

The issue has sparked debate within the embassy, where U.S. Ambassador William Swing has been pressing the development agency to take on the AIDS issue more forcefully, these sources said.

AIDS has been relatively slow in affecting South Africa because of the country's isolation and distance from central and eastern Africa, where the disease is becoming rampant. The government has registered 613 cases of AIDS since 1982, 270 of those last year. But the number of South Africans who test positive for the HIV virus, the cause of AIDS, is predicted to reach up to 446,000 by the end 1991, according to the National Health Department.

Both the South African government and black groups have been slow in acknowledging the danger and only now are beginning to address the problem. Most blacks here still regard AIDS as "a white man's disease," said Dr. Nthato Motlana here. He also accused the government of ignoring the issue. It is spending $2.2 million on its AIDS education and training program this year, only about as much as the Agency for International Development may commit here this year.

A Health Department spokesman said an additional $4 million is earmarked for monitoring blood banks and $1.8 million for condoms, which are given out free. But the latter amounts are for programs reportedly involving all sexually transmitted diseases, not just AIDS, and there are reports the government may cut the AIDS education program up to one-third in the budget starting in March.

The African National Congress, the largest black nationalist group, has admitted to being slow in reacting to the threat. An ANC report issued in June said that because of the "relative unclarity" about the disease and because it relates to sexuality, "an area viewed as taboo," the ANC's health department "started late in looking for responses to it."

"This delayed response has caused the movement to pay a high price," the report said. It attacked the government's "utter insensitivity to this scourge," but conceded that whatever Pretoria does to fight the disease provokes "a suspicious response" from blacks "because the apartheid authorities lack popular legitimacy."