S. Africans Press on Toward Agreement : Negotiations: An accord to end 350 years of white rule likely won’t be reached for months.

JOHANNESBURG, South Africa —  President Frederik W. de Klerk, Nelson Mandela and 17 other South African leaders, their hopes of a quick accord ruined by a negotiating deadlock, agreed Saturday to press on in their search for a formula to end 350 years of white rule.

The decision, reached in an upbeat final session of the Convention for a Democratic South Africa, gives the responsibility for resolving their differences to a convention committee of senior officials. And it means that negotiators will go back to the table in the coming weeks, putting off by at least a few months any accord.

De Klerk, Mandela and other leaders gave upbeat farewell speeches, patting each other on the back for the progress they have managed to make so far on difficult, complex issues.

“We’re on one ship,” De Klerk told delegates in a closing address. “If it sinks, all of us will drown. Let’s keep it afloat.”

Mandela, speaking earlier, said the ANC is pleased with the progress the negotiators have made since December. And he expressed confidence that full agreement about the way forward will be achieved, if not now then in the coming weeks.

“We are going back home full of strength and hope,” Mandela said to applause. “We are all members of one family, and one day we will all be able to deliver the goods” to the country.

The optimistic words appeared designed to boost the spirits of millions of disappointed South Africans. Hopes had been raised in the country that the meeting Friday and Saturday, after five months of behind-the-scenes talks, would approve the first step in the transition to a democratic government.

In fact, that first phase--interim councils to oversee the current government--was agreed to by the 19 political parties participating in the convention.

But an impasse over the second step, during which a nationally elected body will write the new constitution, brought the talks to a temporary halt. The ANC and the government, in the end, disagreed over the percentage of votes that would be required to pass proposals in a constitution-making body. The ANC wanted 70%, and De Klerk’s ruling National Party insisted on 75%.

When a last-minute bid to remove the roadblock failed Friday, the African National Congress and the white-minority government bitterly criticized each other in public, and the negotiation process itself appeared to be in jeopardy.

But De Klerk and Mandela, after an hourlong meeting Friday night, agreed that the negotiating forum, which had come so close to agreement, must continue its work. And both men delivered upbeat speeches at the final session on Saturday, pointing out that an accord reached in haste would be worse than no accord at all.

“We started off on the wrong foot,” De Klerk told the delegates Saturday. “There was crisis in the air. But we’ve managed to transform crisis into success and progress.”

The delegates agreed Saturday to give the convention’s executive committee, on which all 19 parties have a senior representative, broad responsibility to resolve the still-disputed issues. A third meeting of the convention will be scheduled later, perhaps within six weeks, delegates said.

The conciliatory tone of the remarks by De Klerk and Mandela covered the deep distrust that remains between their two parties and, to some extent, between themselves as well. That distrust has made the negotiations process especially difficult.

“You build trust through cooperation, and as we succeed, the trust will grow,” De Klerk told a news conference Saturday. “I’m working on it.”

Mandela stopped to shake hands with De Klerk on his way to the podium Saturday, and the two leaders smiled as they talked earlier that day. But many ANC leaders doubt the government’s sincerity, and they think De Klerk wants to create a complex new constitution that will allow him to maintain substantial political power.

“I still do not have complete trust in what Mr. De Klerk says on the issue of minorities,” admitted Cyril Ramaphosa, the ANC’s secretary general. The government says it wants to protect minorities, such as whites, from domination by a black government. The ANC suspects, though, that what the government really wants is a minority veto.

Mandela spared no criticism of the government in his remarks.

He said the recent disclosures of alleged government security force involvement in the violent deaths of anti-apartheid activists “confirm the view that the sooner all our people are able to decide who should govern the country, the better.”