South Africa's ruling ANC will announce on Thursday the verdict of a disciplinary hearing that could derail the political career of its outspoken youth leader Julius Malema.

Malema, a party power broker and leading advocate for the nationalisation of mines, has been charged with sowing divisions in his party. The ANC will hold a news conference at 0800 GMT.

The Star newspaper, quoting unnamed sources, reported on Wednesday that the chairman of the disciplinary panel, Derek Hanekom, had recommended Malema be suspended for a year.

The disciplinary case is widely regarded as a showdown between Malema, 30, and President Jacob Zuma, whose path to re-election as head of the ANC could be blocked by Malema.

ANC insiders allege Malema is fronting a plot to oust Zuma and replace him with Deputy President Kgalema Motlanthe.

Malema has unnerved investors with his calls for state ownership of mines and a seizure of white-owned farm land. He has also won legions of supporters among South Africa's poor black majority who regard him as a future leader.

If Malema were suspended for a year he could be back in his post as the ANC's Youth League President in time for a major ANC meeting in December 2012.

ANC spokesman Keith Khoza indicated action could be taken against Malema. There are complications with the ANC constitution and the ANC Youth League constitution in terms of his standing as a leader of the youth league, Khoza said.

Malema was found guilty of a separate disciplinary violation a year ago but was allowed to keep his post after being given a two-year suspended sentence.

Any penalty imposed on Malema will not automatically result in him being removed from ANC structures and the public arena.

He can appeal to the ANC's highest decision-making body, the National Executive Committee, headed by Zuma, and at the party's national elective conference in December 2012.

Zuma could fail in his bid for re-election as head of the ANC if Malema rallies support against him.

Zuma's foes have been courting Malema as they line up their bids for power. The head of the ANC is almost assured of the presidency given the party's stranglehold over politics.

Motlanthe and former youth league leader Fikile Mbalula have denied they are part of a plot. The ANC discourages succession debates outside party structures.

I do not get involved in plots about anything. If there is something I want to say, I say it within the ANC, Mbalula told the New Age newspaper. This is something I can be killed for because some people may believe these lies.

In what might be a sign of Malema's influence on Africa's largest economy, credit ratings agency Moody's lowered its outlook on South Africa.

It voiced concern that political pressure from black voters wanting greater economic redress for the ills of apartheid could erode the country's finances.