Harare - A month-long standoff between Zimbabwe's political parties over the implementation of a power-sharing deal appeared to be at an end Thursday, with sources saying President Robert Mugabe and his arch-rival Morgan Tsvangirai had agreed on a composition of a unity government.

"An acceptable compromise has been reached," a senior official from Tsvangirai's Movement for Democratic Change (MDC) told Deutsche Presse-Agentur dpa on condition of anonymity, on leaving the talks at an hotel in Harare.

A senior source within Mugabe's Zanu-PF also said three days of marathon talks brokered by former South African president Thabo Mbeki had ended successfully, without giving details.

In a further indication that the impasse had been resolved South African radio quoted Zimbabwean sources as saying that Tsvangirai would be sworn in as prime minister Friday.

The historic September 15 power-sharing deal between Mugabe, Tsvangirai and MDC splinter faction leader Arthur Mutambara had looked to be on the shaky ground earlier this week, amid a bitter dispute over the sharing of cabinet posts between the parties.

At the weekend Mugabe was insisting on holding all the key ministries, prompting Tsvangirai to threaten to pull out of the deal. Tsvangirai's party has the most seats in parliament.

Under the September deal, Zanu-PF and the two MDCs are to share the ministries, with 15 going to Zanu-PF, 13 to Tsvangirai's party and three to Mutambara's. (dpa)