Powersharing talks between Zimbabwean President Robert Mugabe's Zanu-PF party and the opposition Movement for Democratic Change broke down Monday, sources within and close to to the MDC reported.

An MDC official in Zimbabwe told Deutsche Presse-Agentur dpa that the talks had reached an impasse over the distribution of posts in the proposed new government.

A Western NGO source close to the MDC also confirmed the talks had hit a stalemate.

Representatives from Zanu-PF and two factions of the MDC - the majority faction led by Morgan Tsvangirai and a smaller faction led by Arthur Mutambara - began talks four days ago on the formation of an 'inclusive' government, as called for by the African Union at a summit in June.

The talks, scheduled to take place over two weeks in South Africa, had always been expected to be difficult, given deep-seated enmity between Mugabe's party and Morgan Tsvangirai's nine-year-old MDC.

The MDC official told dpa that Tsvangirai's position in the proposed unity government was unclear.

The MDC defeated Zanu-PF in March parliamentary elections, and Tsvangirai took more votes than Mugabe in the first round of voting for president on the same day.

Mugabe went on to contest the violent run-off election solo and was inaugurated as president in late June for a further five years.

The MDC has proposed that Mugabe remain on as president with reduced ceremonial powers and that Tsvangirai would occupy a new executive prime ministerial post.

But Zanu-PF has ruled out Mugabe having anything other than a leadership role in the new government.