David Dacko, who recently came to power here in a French-led coup, said today the embattled Central African Republic will establish official relations with South Africa.

Dacko, 49, made his surprise announcement at a half-hour press conference in the posh Palais de la Renaissance, which until Thursday was the government headquarters of deposed emperor Bokassa.

The new self-proclaimed president also said he will seek the extradition of Bokassa from the Ivory Coast, where the overthrown dictator sought asylum after France refused to harbor him.

If Dacko follows through on his intentions toward South Africa, his will be the second black African country -- Malawi is the first -- to have diplomatic relations with the apartheid government. The South Africans, officially anathema to most of black Africa, have extensive but unofficial trade relations with a number of African countries.

Central Africa's new ruler indicated in response to questions that his motive for establishing open relations with South Africa is economic. Diplomatic sources said today that the South Africans had been pouring money into this country for some time when it was known as the Central African Empire under Bokassa.

"I will maintain relations with South Africa," Dacko said, "But instead of doing it [surreptitiously], I will do it officially."

"If the South Africans can exploit our oil and our diamonds," he added," I will do it officially." Oil exploration has shown that Central Africa has an as yet unmeasured amount of oil, and diamonds are the country's largest revenue earner.

The South Africans are presently fi202.2nancing the construction of more than $300 million Intercontinental Hotel, were building a slaughterhouse near Bokassa's former imperial residence at Berengo and constructed a large housing compound for visitors during his ostentatious coronation two years ago.

Bokassa kept his ties with South Africa secret, but Dacko said there "will be no embarrasment" on the part of his government to begin official relations.

Dacko was the Central Africian Republic's first elected president when it became independent from France in 1960 and was overthrown by Bokassa in a coup on New Your's Eve in 1965.

He spent 3 1/2 years in Bangui's infamous Ngaragba Prison, where hundreds of Bokassa's political opponents reportedly died.

After release from prison and a period under house arrest, Bokassa made Dacko a close adviser, until Dacko fell out with the erratic emperor last June. Dacko is also a cousin of Bokassa's.

After their confrontation, Dacko, who is asthmatic, feigned illness and flew to Paris, ostensibly for treatment.

The Estrangement between the two men began after public accounts surfaced about the killing of 100 schoolchildren here. The pupils had demonstrated against a requirement to buy uniforms made from cloth produced at a factory owned by Bokassa's wife.

Both Amnesty International and a five-nation African investigating commission made public charges about the massacre. The commission reported that Bokassa participated in the murders, a charge that Dacko echoed here recently.

Since seizing power, Dacko has said that Bokassa's prime minister, Henri Maidou, was also in on the plot. Maidou, whom Dacko has appointed his vice president, called Dacko in Paris after Bokassa flew to Libya Wednesday morning and told him the emperor would be out of the country for 48 hours, one reliable source said.

Dacko then flew into Bangui Thursday night from neighboring Ndjamena, Chad, as French paratroopers came in from Chard, Gabon and Zaire.

Dacko has said the French troops flew in after he made a telephone call, but witnesses said French troops were in the streets of Bangui a good while before Dacko made his 11:55 p.m. broadcast that he had taken over.

French President Valery Giscard d'Estaing, whose family has commercial interests here, is known to have been embarrassed and angered about the deaths of the schoolchildren.

France, which heavily subsidized Bokassa's $25 million coronation in December 1977, supplied 69 percent of the country's annual $90 million budget. Much of that budget and foreign aid grants allegedly were siphoned into overseas bank accounts by Bokassa and some of his aides. France ended its assistance in June.

Bokassa, a Western source said, had strained to meet the payroll for his 800-member Imperial Guard and the country's civil servants. In August, he wen to Libya's Muammar Qaddafi to seek funds, the source said.

"He never would have thought of taking money out of his own pocket," the source added.

A source in Paris said Saturday that the French decided to move on Bokassa because he was about to make a deal with Qaddafi to provide the Libyans with a military base in northern Central Africa in exchange for funds.

Dacko, dressed in a conservatively cut gray suit, joked and laughed during his press conference today. The heavy-set ruler denied an announcement made today over his government's radio that Bokassa had been condemned to death.

In response to questions, Dacko said relations between Ivory Coast President Felix Houphouet-boigny and his government will remain good even if the Ivory Coast refused to extradite Bokassa.

"One man does not determine relations between two countries," Dacko said.

The estimated 1,000 French troops here now, he added, "will remain as long as 10 years or as long as they are necessary."

Dacko also announced that elections will be held in six months for a constituent assembly to draw up a new constitution and he will allow the formation of political parties.

In future elections, Dacko added, the party that wins the most votes will be "the party." Only one party existed under Bokassa.