Pretoria said to secretly offer to talk to ANC. But speech by black nationalist leader indicates ANC skeptical about Pretoria's intentions

The South African government has secretly proposed a high-level meeting with the banned African National Congress, but the black-nationalist organization has responded cooly to what it views as a political trick. The report of South African overtures came yesterday from informed sources at an international conference here of anti-apartheid activists. The parley, called to discuss ``children, repression, and the law'' in South Africa, has attracted some 300 delegates - from South Africa, Europe, and the ANC's headquarters in Zambia.

The report coincided with a public broadside by ANC President Oliver Tambo on Pretoria's announced plan to negotiate ``power sharing'' with the country's black majority. Addressing the conference, Mr. Tambo accused the South African government of trying ``to give racial tyranny a new face.'' He said any resolution which fell short of full black-majority rule was unacceptable.

The twin developments here amounted to a new setback in Pretoria's move to establish a National Statutory Council for talks on power sharing.

The report of secret attempts to talk with the ANC - which Pretoria defines as a Communist-inspired ``terrorist'' movement - may redouble pressure from right-wing whites. Tambo's rejection of the council idea, meanwhile, will complicate official efforts to bring a credible cross-section of black leaders, including ``radicals,'' into power-sharing talks.

In a meeting with reporters last week, presidential aide Stoffel van der Merwe said he held out hope that the ANC might eventually join the Statutory Council. But he said he saw no sign that the ANC was ready to meet a government challenge to ``abandon violence'' and join ``peaceful negotiations.''

There was no immediate response available from South Africa of the reported overtures to the ANC. Asked about such contacts last week, Mr. Van der Merwe said he was unaware of any feelers, saw no urgent need for them, but would not necessarily be aware of any.

The sources here said Pretoria had made two indirect offers since July ``to send a cabinet minister'' to meet with the ANC.

The ANC, said the sources, replied to the offers by asking, ``Which minister? And what would he want to talk about?'' They said Pretoria had not yet replied.

But they said Tambo's speech should be read as reflecting deep ANC skepticism over the feelers. At a minimum, they indicated, the ANC would insist that Pretoria agree to three things before any meeting: that the talks would be made public beforehand; that imprisoned black politicians, including ANC veterans like Nelson Mandela, would be unconditionally released; that the ANC would be unbanned.

Tambo's address didn't mention secret feelers. But he did refer to ``all manner of noises about'' negotiations. And he charged that Pretoria ``is not interested in any genuine negotiation - that would lead to the transfer of power to the people through a system of one person, one vote in a united, democratic, and nonracial South Africa.''

The government, Tambo said, was seeking to ``maneuver'' - to retain ``the apartheid system'' while undercutting moves toward further international economic sanctions. Conference sources said the ANC felt a particular aim of Pretoria was to help British Prime Minister Margaret Thatcher head off talk of further sanctions at next month's Commonwealth summit in Canada and to press instead for the ANC to enter talks with the South African government.

The ANC is understood to feel that this would facilitate Pretoria's efforts to offer blacks a limited share of national power as an alternative to a one person, one vote majority voice.

The sources here added that the ANC is concerned that to meet with South African officials under present political circumstances would risk sapping the morale of antigovernment activists inside the country, many of whom might assume the ANC was ``selling out.''