* Four arrested for suspected bomb conspiracy
* ANC says conference marquee targeted
* Fringe Afrikaner group admits members arrested
BLOEMFONTEIN, South Africa, Dec 17 (Reuters) - South African police said on Monday they had foiled a plot by suspected right-wing Afrikaner extremists targeting an African National Congress (ANC) conference attended by President Jacob Zuma and dozens of top government officials.
Four men aged between 40 and 50 were arrested on Sunday. A police spokesman said there was evidence they were planning acts around the country and not just at the ANC meeting in the central city of Bloemfontein.
The vast majority of South Africa's whites accepted the ANC's victory in the 1994 election that brought Nelson Mandela to power and ended decades of white-minority rule. However, a tiny handful continues to oppose the historic settlement.
"Their acts are widespread. We arrested them in different provinces," spokesman Billy Jones told Reuters.
ANC spokesman Keith Khoza said preliminary information suggested the men were planning to bomb the marquee where Zuma and 4,500 delegates are holding a five-day meeting to chose the ANC's leadership for the next five years.
"This would have been an act of terrorism that South Africa can ill afford," Khoza said.
The Federal Freedom Party (FFP), a fringe group fighting for self-determination for the white Afrikaner minority, confirmed two of those arrested were FFP members but denied any role in the suspected plot.
"We were not involved and do not associate ourselves with their actions," FFP national secretary Francois Cloete told Reuters.
In July, a former university lecturer was found guilty of orchestrating a 2002 plot to overthrow the ANC and assassinate Mandela - now 94 and receiving treatment in a Pretoria hospital for a lung infection.
There was a heavy security presence at the Bloemfontein meeting and the few vehicles being allowed onto the university campus hosting the event were being searched by police and sniffer dogs.
ZUMA AND CYRIL
The conference is set to give Zuma a second mandate to lead the party and - given the ANC's dominance at the ballot box - another five-year term in 2014 as president of Africa's biggest economy.
Zuma's nomination for the post of party leader was met by wild cheers from delegates, in marked contrast to the muted applause and occasional whistle that greeted his only challenger, Deputy President Kgalema Motlanthe.
Motlanthe withdrew from the race to become Zuma's number two, virtually handing the position to former union leader Cyril Ramaphosa, South Africa's second-richest black businessman who is returning to politics after a decade absence.
Ramaphosa supporters were confident of victory when results of the internal election are announced on Tuesday.
"The numbers are in our favour and we are going for it," said one backer said. "It's almost a done deal. Cyril is going to be our next deputy president."
The ascension of Ramaphosa to a top ANC position is likely to be seen as a pro-business move by a party still deeply rooted in socialism, and may help assuage the fears of the ratings agencies that have recently downgraded South Africa.
Zuma's administration has been criticised for failing to overhaul a rigid labour market or fix a broken education system that is eroding the long-term competitiveness of Africa's biggest economy.
There are also concerns the ANC might push for new taxes for mining firms to help the government finance welfare spending for the millions of blacks who have seen few economic gains since the end of apartheid.
However, Deputy Finance Minister Nhlanhla Nene said the government would not be "reckless" in implementing new taxes. He also accused the ratings agencies of political meddling.
"There has actually been some level of unfairness because if you look at what was coming out of the ratings agencies, it was somewhat of an attempt to influence the outcome of the conference," he told a business forum on the sidelines of the ANC meeting.