Ramaphosa, a former trade unionist, was the African National Congress' chief negotiator during talks that led to a peaceful end to apartheid in 1994 and Nelson Mandela becoming South Africa's first black president.

Ramaphosa has said he has no interest in becoming South Africa's next president but he would likely be a leading contender if he changes his mind, analysts say.

Kader Asmal, a member of the ANC's National Executive Committee and former cabinet minister, said he nominated Ramaphosa for the party's presidency last week at the powerful Gaby Shapiro branch of the party in Rondebosch, Cape Town. The branch includes five cabinet ministers.

"I used my right as a member and senior member of the ANC to propose his name and it was accepted overwhelmingly, no other nomination got double figures," Asmal to Reuters.

"I hope there would be hundreds of branches that nominate him, because in my view he is the most suitable person to be president of the African National Congress and the president of South Africa."

Asmal said he had not spoken to Ramaphosa about joining the race and it was up to him to decide.

The ANC, which enjoys an electoral stranglehold on South African politics, holds a conference in December that will elect a new party leader, who will almost certainly become South Africa's next president, replacing Thabo Mbeki.

The ANC leadership race has so far focused on Mbeki and ANC Deputy President Jacob Zuma, a rivalry that has helped plunge the party into some of the worst infighting in its history and could cause further damage as the race heats up.

Mbeki is constitutionally barred from serving again when his term expires in 2009, though nothing prevents him from running for another term as leader of the ANC.