S.Africa to choose Kgelema Motlanthe as interim president

South Africa's parliament is expected on Thursday to appoint ruling ANC deputy head Kgalema Motlanthe as interim president of a country gripped by the most serious political crisis since the end of apartheid.

Thabo Mbeki resigned on Sunday as head of state after the ANC withdrew support following a judge's suggestion of official interference in a graft case against party leader Jacob Zuma, widely expected to become president after next year's election.

Almost one-third of South Africa's cabinet stepped down on Tuesday out of loyalty to Mbeki, who presided over South Africa's longest period of growth.

The political upheaval has raised concerns that the worst divisions in the history of the ruling African National Congress will deepen.

Mbeki will not attend the swearing in ceremony of his successor, parliament officials said, in a sign of the political tensions. "Mbeki was invited but has declined," said an official in parliament's protocol office.

South African parliamentary speaker Baleka Mbete, is expected to be appointed state deputy president, officials said.

"The chief whip said so this morning," Zizi Kodwa, an official in the presidency told Reuters.

Mbete will replace Phumzile Mlambo-Ngcuka, who resigned on Tuesday together with 10 other cabinet ministers out of loyalty to Thabo Mbeki, who stepped down as president on Sunday.

The resignation of Finance Minister Trevor Manuel shook markets but they partially recovered when he said he would be happy to serve under the new president.

Motlanthe, a left-leaning intellectual and Zuma ally, is widely respected by both the radical leftists and business tycoons within the African National Congress.

A former student activist and trade unionist, Motlanthe is seen as a figure who could help heal rifts in the ANC and calm nerves over South Africa's turmoil.