(CNN) -- Embattled Zimbabwean President Robert Mugabe signed a power-sharing deal with the opposition party's breakaway faction, his party said Tuesday, though Mugabe's opponents denied the claim.





Zimbabwe President Robert Mugabe leaves a hotel where negotiations had been taking place Tuesday.





Mugabe's party said the deal, which promises cabinet positions to the splinter group of the Movement for Democratic Change, does not involve MDC head Morgan Tsvangirai.





Tsvangirai said he still is involved with the talks, and that the power-sharing deal with the MDC offshoot is part of larger deal that has not been signed by anyone. Welshman Ncube, spokesman for the MDC splinter group, also said his party has not signed a deal with Mugabe, though Mugabe's party said the deal was signed with the group's chief, Arthur Mutambara.





South African President Thabo Mbeki, the mediator in the talks, would not confirm that a deal had been signed. Mbeki said Mugabe and the splinter group had formed an "agreement" and were awaiting Tsvangirai's position on certain points in the plan.





Another high-ranking official with knowledge of the negotiations told CNN that the deal signed with Arthur Mutambara, head of the faction that broke from the MDC, has to do with the prime minister position that will be created in the new Zimbabwe government.





The official said deciding the duties of the new prime minister has been a sticking point in the negotiations. The MDC has wanted the prime minister to be in charge of government and Mugabe to be in charge of the state, the official said.





But Mugabe has sought to keep control of both and make the prime minister position "ceremonial," the official said.





All the parties involved have been meeting in a hotel in Harare, Zimbabwe's capital city. Video footage Tuesday showed Tsvangirai leaving the negotiations stone-faced as he ignored reporters' questions.





Mutambara told reporters he plans to have a news conference Wednesday, and Mugabe smiled widely and shook hands with onlookers as he left the hotel, but did not answer reporters' questions.





Tsvangirai had been in power-sharing talks with Mugabe in recent days as a culmination of his party's protest of Mugabe's disputed re-election in a June presidential runoff. The election was condemned internationally as a sham.





Tsvangirai withdrew from the June 27 runoff days before the vote, saying Mugabe's supporters had orchestrated a campaign of beatings, intimidation and murders against the MDC.





Tsvangirai had garnered the most votes in a March general election, but not enough to avoid a runoff, according to the government's official count.





CNN's Nkepile Mabuse contributed to this report.
What says official about opposition? Who denies discussions? Who is not part of the deal? Who makes power-share deal with splinter group? Who denies he's out of power-sharing discussions? Who made a power-share deal with a splinter group? Who is  not part of deal, official says?
deciding the duties of the new prime minister has been a sticking point in the negotiations. Mugabe's opponents Thabo Mbeki, Robert Mugabe Mugabe's opponents Robert Mugabe Morgan Tsvangirai.
question: What says official about opposition?, answer: deciding the duties of the new prime minister has been a sticking point in the negotiations. | question: Who denies discussions?, answer: Mugabe's opponents | question: Who is not part of the deal?, answer: Thabo Mbeki, | question: Who makes power-share deal with splinter group?, answer: Robert Mugabe | question: Who denies he's out of power-sharing discussions?, answer: Mugabe's opponents | question: Who made a power-share deal with a splinter group?, answer: Robert Mugabe | question: Who is  not part of deal, official says?, answer: Morgan Tsvangirai.