HARARE, Oct. 8 (Xinhua) -- Negotiators from Zimbabwe's ruling Zanu-PF and the two opposition MDC (the Movement for Democratic Change) formations met in Harare on Tuesday but could not conclude the allocation of the two remaining ministries, the Finance and Home Affairs, the Herald reported on Wednesday.

    The negotiators met inconclusively for about two hours, prompting South Africa's ruling African National Congress to urge the parties to continue consulting until they reach an agreement.

    ANC leader Jacob Zuma on Tuesday said Zimbabwe's main political parties should keep talking to resolve an impasse in forming a Cabinet under a power-sharing deal signed on September 15.

    But Zuma said if outside mediation was needed, he was confident that former South African president Thabo Mbeki could step in to assist in breaking the deadlock.

    "I am hoping that it is going to be resolved by Zimbabweans themselves.They just have to negotiate with themselves and find a solution," Zuma said in an interview on South African FM radio.

    "What is happening now is a challenge to the leadership . . . to exercise responsibility as the leaders and the political parties for the sake of the country," the ANC leader said.

    But Zuma commended Mbeki's mediation efforts, saying he is confident that the former president could return to Zimbabwe if his help was needed again.

    Zimbabwe's power-sharing deal is teetering on the brink of collapse after the Movement for Democratic Change (MDC) negotiators walked out of a critical meeting with Zanu (PF) on Tuesday as a dispute over ministerial posts intensified.

    Three meetings involving President Robert Mugabe and main MDC leader Morgan Tsvangirai have failed to resolve the issue. Mugabe and Tsvangirai met on Saturday for the third time, but deadlocked over the distribution of ministries.

    Under last month's power-sharing agreement, Mugabe is entitled to 15 ministries, Tsvangirai 13, and the leader of the smaller MDCfaction Arthur Mutambara three.

    Mugabe is allowed eight deputy ministers, Tsvangirai six and Mutambara two. However, there is no agreement on which portfolios go to which party.

    There is also a dispute over the sharing of the 10 posts of provincial governors now held by the ruling ZANU-PF. Mugabe's party is also demanding revision of the agreement signed on September 15 to remove a clause which says if any of the parties lose an MP, they would not contest by-elections against each other.

    MDC negotiators said they were "poles apart" from their Zanu (PF) counterparts.

    MDC negotiator Tendai Biti confirmed the meeting broke down because "we were worlds apart".

    "Zanu (PF) came into the meeting with an arrogant and contemptuous attitude," he said.

    Biti said the allocation of all 31 ministries had not yet been resolved, adding that in view of the "interminable deadlock", Mbeki needed to help resolve the issue.

    Zanu-PF negotiator Patrick Chinamasa said earlier that the party did not see the need for Mbeki to intervene yet.