* Diplomats worry that South Africa may not press Gbagbo
* Zuma sees no reason for Gbagbo exile
By Jon Herskovitz
PRETORIA, Jan 21 (Reuters) - South African's president said on Friday there were uncertainties over the Ivory Coast election about both main candidate sides, although global powers believe the vote was clearly won by a rival to Laurent Gbagbo.
The statement from Jacob Zuma, the leader of Africa's biggest economy, could add to worries his government may be a weak point in regional efforts to force Gbagbo, who became president in 2000, to step down.
"We believe that there also some discrepancies in the manner in which the election ... has come to the final pronouncement of the vote," Zuma said at a news conference after holding talks with Uganda President Yoweri Museveni.
The African Union's mediator for Ivory Coast planned talks with the leaders of Angola and South Africa this week, trying to prod them into taking a firm stand in ending Gbagbo's rule.
"Angola is the weakest partner in AU unity," said a diplomat on Thursday who is following the Ivory Coast crisis, adding South Africa has also not weighed in as strongly as some had hoped. [ID:nLDE70J17B]
The United States, European Union, United Nations and others have stated that Alassane Ouattara won the Nov. 28 vote. Ivory Coast, the world's top cocoa grower, has been paralysed since the presidential election.
Ouattara was proclaimed winner by the electoral commission and is internationally recognised as president-elect, but Gbagbo, who retains control of the military, has refused to go, alleging the vote was rigged.
Ivory Coast's pro-Gbagbo Constitutional Council cancelled hundreds of thousands of votes in Quattara strongholds to reverse his win.
Military chiefs of West African regional bloc ECOWAS met in Mali on Tuesday to discuss the planning of an ouster of Gbagbo.
Zuma did not throw his support behind a proposal floated by diplomats for Gbagbo to go into exile, a move they believe could help end the crisis and ensure a peaceful transition of power.
"If we believe that somebody has lost the election, why do we call for somebody to leave the country?" Zuma said, without making any critical comments of Gbagbo.
Zuma said he felt an African Union meeting next week in Ethiopia might be able to "deal with the matter". (Reporting by Jon Herskovitz; Editing by Matthew Jones)