Harare  - Negotiators for Zimbabwe's political parties began a fourth day of power-sharing talks Thursday under the mediation of South African President Thabo Mbeki amid waning hopes of deal in the coming days.

President Robert Mugabe, Movement for Democratic Change (MDC) leader Morgan Tsvangirai, and Arthur Mutambara, leader of a breakaway MDC faction, were expected to join the talks later in the day.

Mbeki has been in Zimbabwe since Monday trying to push Mugabe and Tsvangirai the final mile towards a deal. Mbeki is the Southern African Development Community's mediator in Zimbabwe.

The defence panel of the 15-nation regional grouping, which had been due to meet Wednesday in Swaziland to discuss progress in the mediation, postponed the meeting for a second time.

"They are waiting for the talks in Harare to finish to get a report from President Mbeki as to how everything has gone," Swazi government spokesman Percy Simelane told Deutsche Presse-Agentur dpa.

Though Mugabe and Tsvangirai both said there had been further progress when they left the meeting Wednesday night - Tsvangirai said there was "very little work left" - sources close to the talks and state media said prospects of clinching a deal Thursday were "slim."

"Despite public pronouncements by the leaders that a deal was on the horizon, insiders revealed that little progress was made yesterday and the prospects of a settlement this week now appeared slim," the state-run daily The Herald said.

Mugabe was cited by the paper as telling Mbeki he would appoint a cabinet this week regardless of the outcome of the talks Thursday.

"He (Mugabe) apparently indicated (to Mbeki) that the country had gone too long without a substantive government and the situation was now untenable," the report said.

The MDC has said such a move would end the talks.

The Herald also reported that Swazi King Mswati III, who chairs the SADC security troika, was on standby to fly into Harare should an agreement be reached Thursday.

On Tuesday, Mugabe and Tsvangirai had expressed cautious optimism that the talks would be concluded Wednesday. But a senior member of Mugabe's Zanu PF close to the negotiations told dpa: "We've still a long way to go since the MDC flip-flops a lot and confuses everyone."

Mugabe and Tsvangirai have been at loggerheads over how to share executive powers if, as proposed, Mugabe remains president and Tsvangirai becomes prime minister. The question of who would chair cabinet has been particularly fraught.

Sources from both sides said a compromise had been put forward, which would see Mugabe chair cabinet and Tsvangirai chair a council of ministers. The sources said there was agreement on the proposal. It was not possible to get official confirmation.

Other issues yet to be resolved were the positions of deputy prime ministers and the MDC's objection to Mugabe's appointment of regional governors last week - a move the MDC says contravenes the ground rules for the talks.

It was also not clear whether they had reached agreement on the duration of the new government. The MDC was originally calling for a 2.5-year transitional authority.

"Mugabe's argument is that he cannot dismiss the governors he appointed just last week, but given that this is a power-sharing arrangement, we can't allow Zanu PF to have all 10 governors," an MDC source said.

The MDC took the most votes in March legislative and presidential elections. Mugabe won a later presidential run-off that only he contested and that widely denounced as a sham. (dpa)