South Africa Sets Talks on Constitution : Negotiations: The government, ANC and Inkatha tentatively agree on Dec. 20-21 to discuss ending apartheid.

After 18 months of fragile talks about talks, the government, the African National Congress and the Inkatha Freedom Party announced tentative agreement Thursday on Dec. 20-21 for the first round of formal negotiations on this nation’s future.

And a meeting of almost two dozen black and white political groups was scheduled for next Friday to prepare for the negotiations, expected to lead to an interim government and a new constitution that will extend voting rights to the black majority.

The announcement ended weeks of behind-the-scenes bickering about who should be involved in planning the formal negotiations. But it also signaled the beginning of what most analysts believe will be an even more contentious phase of constitutional negotiations that may continue for a year or longer.

ANC spokesman Saki Macozoma called the announcement “a significant breakthrough,” and other political leaders agreed that it is an important step.

“The time to begin sowing the seeds of national healing and reconciliation is now,” ANC President Nelson Mandela said Thursday in a speech in Johannesburg. “The alternative is anarchy, chaos and more violence.”

He said it is the duty “of every patriot” to work toward consensus “on the imperative need to eradicate apartheid in all its ramifications.” And he added that all South Africans “must be prepared to locate and accommodate those (with whom we have) differences, which are inevitable.”

Political leaders warned, though, that deep differences among South Africa’s black and white political organizations still threaten to derail negotiations. And the public sniping between Mandela and President Frederik W. de Klerk has increased in recent weeks.

De Klerk, in a speech this week, expressed confidence that a broad consensus on a new constitution could be reached despite “obvious differences.” And he said his government would “implement and abide by the new constitution.” But he vowed that the government would not accept, under any circumstances, “a constitution in which the winner takes all” or a system, such as that favored by the ANC, that would experiment with socialism.

“We are not prepared to abdicate power to assist the ANC or anybody else to misuse power and suppress minorities,” he said.

Most of the major political groups in the country said Thursday that they will attend next week’s plenary session, during which decisions will be made on the site for the December talks, as well as the crucial question of who will convene those talks.

The ANC and its allies have said they favor neutral conveners, such as church leaders. Among the names of possible chairmen often mentioned are: Johan Heyns, former leader of the Dutch Reformed Church, the largest white church in the country, and Methodist Bishop Stanley Magoba, a black leader who is co-chairman of the National Peace Committee.

The groups that have agreed to participate in the talks include the left-wing Pan-Africanist Congress, the liberal white Democratic Party, the South African Communist Party and the 1.2-million-member Congress of South African Trade Unions.

The right-wing white Conservative Party, whose participation is considered crucial to the success of any negotiations, said it will decide whether to participate once it receives an invitation. But the Conservatives, who represent one in four white voters, have indicated that they will refuse to join the talks unless guaranteed a separate white state. Neither the government nor the ANC has been prepared to make such a guarantee.

The Azanian People’s Organization, which represents a small number of younger, militant blacks, said it will not participate without firm assurances that the white-minority government intends to hand over power to the black majority.

The government said the number of participants and venue for the planning session have not been made final. But government sources said the meeting probably will include three delegates from each of 22 political groups, including black homeland leaders.