Oct. 9 (Bloomberg) -- Former South African President Thabo Mbeki has agreed to return to Zimbabwe to help break a deadlock over the formation of a unity government, opposition leader Morgan Tsvangirai said.

Mbeki will resume his ``facilitation role'' in talks to form a coalition government between two factions of the opposition Movement for Democratic Change and President Robert Mugabe's Zimbabwe African National Union-Patriotic Front party, Tsvangirai said today by phone from Harare, the capital.

``We have now declared a deadlock in the negotiations over ministries and requested the facilitator resume his role,'' he said. ``He has responded and said he will come over.''

Tsvangirai's statement came a day after the African Union and the Southern African Development Community issued a joint statement saying they would ``spare no effort in supporting'' an agreement Mugabe and Tsvangirai signed on Sept. 15. That deal laid out the framework of a power-sharing government, without specifying which parties would head individual ministries.

Zanu-PF's chief negotiator at the talks, Patrick Chinamasa, said Mbeki wasn't needed.

``We aren't going to negotiate this process through the press,'' Chinamasa said today by phone from Harare. ``Local disagreements over this or that don't require an outside facilitator.''

Talks between Zanu-PF, the MDC and a smaller wing of the MDC led by Arthur Mutambara have snagged over the allocation of powerful ministries such as finance and home affairs, which controls the police.

`Bad Man'

``Good negotiations with a bad man aren't easy, but it isn't true that the talks have failed,'' Tsvangirai said today. ``They have deadlocked, though, and that's why we need the facilitator to return.''

The Sept. 15 agreement leaves Mugabe, 84, as president of Zimbabwe, while Tsvangirai will become prime minister. The two men will form a 31-member cabinet with Zanu-PF taking 15 ministerial posts and the two MDC factions taking 16.

Mugabe would head the cabinet and Tsvangirai would preside over a newly formed ministerial committee. No further details have been agreed, the MDC has said.

Under the accord, Mugabe would be able to extend his 28 years in power even though his party lost control of the lower house of parliament in elections last March for the first time since Zimbabwe won independence from the U.K. in 1980.

While Tsvangirai also defeated Mugabe in the first round of a presidential poll, he didn't garner the more than 50 percent needed to avoid a second round of voting. He boycotted the run- off in June because he said Mugabe's supporters had attacked and killed more than 100 MDC Supporters and made thousands homeless.

To contact the reporters on this story: Brian Latham via Johannesburg at pmrichardson@bloomberg.net.

Last Updated: October 9, 2008 08:36 EDT