HARARE (Reuters) - Zimbabwe's main opposition party warned on Monday a deadlock over the allocation of cabinet posts threatened a fragile power-sharing agreement it reached with President Robert Mugabe earlier this month.

A meeting over the weekend between negotiators from Mugabe's ZANU-PF, Morgan Tsvangirai's Movement for Democratic Change (MDC) and a breakaway MDC faction to sort out who gets which posts failed to break the impasse.

Tendai Biti, secretary general of the MDC, said disagreements remained over the allocation of ministries and posts for 10 provincial governors and said this might require renewed mediation. "Fundamentally, we have a deadlock threatening the whole process, not only over the ministers but the governors as well," Biti told Reuters.

ZANU-PF officials were not available for comment.

The MDC said that while it did not oppose Mugabe taking charge of the army, he insisted on keeping control of all key ministries, including home affairs -- in charge of the police -- finance, foreign affairs, justice, information and local government which oversees local councils.

Tsvangirai's party is expected to get 13 cabinet posts in the new government, Mugabe's ZANU-PF 15 and Arthur Mutambara's breakaway MDC faction three.

The landmark political deal was mediated by the ousted South African President Thabo Mbeki and millions of Zimbabweans hope it will be the first step towards rescuing a nation shattered by economic collapse.

Under the deal, Mugabe retains the presidency and chairs the cabinet while Tsvangirai becomes prime minister, chairing a council of ministers supervising the cabinet.

Biti said the MDC did not expect Mbeki's resignation as South African president to affect the unity agreement.