Updated

South Africa's ruling party demanded that President Thabo Mbeki resign and he reluctantly agreed Saturday, as his long-running battle with rival and heir apparent Jacob Zuma reached a crescendo that will reverberate across Africa's economic powerhouse.

Mbeki had been under heavy pressure from his own party to quit following a judge's ruling last week that he may have had a role in Zuma being charged with corruption.

Zuma was not expected to take over immediately. African National Congress secretary-general Gwede Mantashe said Mbeki would remain president until an interim one is appointed. Mantashe also said parliament would meet soon to formalize the process.

He said Mbeki would continue as regional mediator in Zimbabwe, where last week he persuaded President Robert Mugabe to share power with the opposition.

Still, the blindingly swift leadership change has the potential to wreak turmoil in Africa's strongest economy, especially if other key Cabinet ministers decide to quit in solidarity with Mbeki. All eyes were on Finance Minister Trevor Manuel, who shares the credit with Mbeki for South Africa's sustained economic growth and investor-friendly policies over the past decade.

"Following the decision of the National Executive Committee of the African National Congress to recall President Thabo Mbeki, the President has obliged and will step down after all constitutional requirements have been met," the presidency said in a terse statement.

Mbeki's term in office was to have lasted until April 2009.

Several key government executives, including Deputy President Phumzile Mlambo-Ngcuka, had indicated they would follow Mbeki out if he were forced to resign. Mlambo-Ngcuka had replaced Zuma as the country's No. 2 executive after Mbeki fired Zuma in 2005 because of the corruption scandal.

Mantashe said a high-level ANC committee "decided to recall the president" before his term in office expires and that Mbeki had accepted the news graciously.

The president "did not display shock ... he welcomed the news and agreed that he is going to participate in the process," Mantashe said.

Mbeki did not attended the ANC meetings that started Friday and went on all night to decide his fate.

South Africans select parties, not individuals, in presidential, legislative and other voting. That puts a premium on party loyalty and discipline and allows politicians to quickly make what might seem to outsiders revolutionary changes.

In this case, South Africans have been expecting the shift from Mbeki to Zuma at least since December 2007, when Zuma beat his former mentor in an internal election for leadership of the party.

Mantashe said Zuma was meeting with Cabinet ministers to persuade them to remain at their jobs. He said the top priority at the moment was to focus on "ensuring the smooth running of the country."

"We share the desire for stability and for a peaceful and prosperous South Africa," Mantashe told a news conference.

Mbeki succeeded Nelson Mandela in 1999 and was due to stand down next year. He has devoted his life to the ANC and is regarded as one of Africa's most respected statesmen.

Promoting what he calls Africa's renaissance, Mbeki has mediated in conflicts ranging from Sudan to Ivory Coast to Congo.

For many years, his quiet diplomacy was criticized as ineffective and biased toward Mugabe, the president of neighboring Zimbabwe, but just last week, Mbeki persuaded Mugabe to share power with his opposition. Mugabe's retreat after nearly three decades of unchallenged power was significant, although talks on the formation of a coalition Cabinet have since deadlocked.

Mbeki fired Zuma as his national deputy president in 2005, after Zuma's financial adviser was convicted of trying to elicit a bribe to deflect investigations into a multibillion-dollar international arms deal.

Initial charges were withdrawn against Zuma, but the chief prosecutor announced in December he had enough evidence to bring new ones. This came was within days of Zuma ousting Mbeki as ANC president.

In his ruling Sept. 12, Judge Christopher Nicholson said it appeared that Mbeki and his justice minister had colluded with prosecutors against Zuma as part of the "titanic power struggle" within the ANC. Mbeki has indignantly denied the accusations.

South Africa emerged from years of institutionalized racism in 1994 and entered an era of reconciliation embodied by anti-apartheid icon Mandela. Mbeki took over in 1999 and ushered in sustained economic growth averaging nearly 5 percent a year.

Mbeki has been heralded by the international business community, but his aloofness has alienated many people at home, where millions remain on the margins of society years after the end of apartheid. Zuma, a maid's son who endured an impoverished childhood, emerged as his populist foil.

Mbeki's foes also accuse him of failing to fight the country's crippling crime and downplaying South Africa's devastating AIDS crisis.