Zimbabwe's ruling ZANU-PF party led by President Robert Mugabe and the opposition Movement for Democratic Change (MDC) headed by Morgan Tsvangirai reached a power-sharing deal Thursday.
The details of the agreement and the forming of a unity government will be released Monday, said South African President Thabo Mbeki, the mediator of the talks, at a press conference.
He also said that regional leaders will witness the long-awaiting signing ceremony.
The substantial development in the on-again, off-again talks came after Mugabe issued an ultimatum last week that he would go ahead unilaterally with naming cabinet ministers if Tsvangirai did not sign the power-sharing agreement by last Thursday.
Zimbabwe held presidential and parliamentary elections on March29, in which presidential candidate Tsvangirai received a leading number of votes but failed to win outright.
The ZANU-PF lost its Lower House majority for the first time since independence from Britain in 1980, but MDC won the majority by only a narrow margin.
Negotiations began in July to resolve the impasse resulting from Mugabe's unopposed re-election in June. The vote was boycotted by Tsvangirai, who accused the Mugabe's ruling party of backing the violence against the MDC supporters.
Tsvangirai demands the lion's share of power in the unity government, insisting on respecting the results of the first round of polls, trying to place Mugabe in a largely ceremonial position of head of state, which Mugabe refused to accept, according to reports.
The negotiations were very close to a breakthrough on the eve of the Southern African Community Development summit held in mid-August, but later stalled as Tsvangirai requested to "reflect and consult" on a sticking point in the dialogue.
It was earlier expected that the parties, which also includes a smaller faction of MDC, led by Arthur Mutambara, would reach a deal on Wednesday, as they all expressed optimism after the talks on Tuesday.
The politics and security committee of the Southern African Development Community (SADC) was supposed to meet in the Swazi capital Mbabane Wednesday to speed up the process, but the summit was postponed as positive signs emerged in the talks.
However, there was no breakthrough on Wednesday as expected, arousing doubt about whether a deal can be struck on Thursday as some news reports indicated.
Though it is yet to know how the power will be allocated in the future unity government, analysts believe that the agreement marks an end to the country's political deadlock and brings hope for the country's economic recovery.
Since 2000, when the country began to undertake a massive land reform program, which was followed by sanctions imposed by the West, the economy has kept declining.
The country, once hailed as Africa's breadbasket, with well cultivated agriculture, the backbone of its economy, is having the world's highest inflation -- 11.2 million percent in June, according to official figures.
It also suffers serious shortage of foreign currency and basic goods like sugar and cooking oil.