The Thai prime minister and the anti-government core leaders will hold negotiation at 4 p.m. on Sunday, anti-government leader Nattawut Saikua disclosed.
Both sides said they believed the negotiation will bring the country out of the political conflict.
Speaking at the red-shirted stage in capital Bangkok, Nattawut said he was informed of the negotiation time with the prime minister through a telephone call from Kobsak Sabhavasu, prime minister' s secretary-general.
The red-shirted stance has remained that the prime minister should dissolve the Lower House of Parliament, Nattawut said.
Three red-shirted core leaders, Veera Musikapong, Jatuporn Prompan and Weng Thojirakarn, will attend the negotiation with the prime minister, he said.
The negotiation venue is planned at King Prajadhipok's Institute in capital Bangkok.
The red-shirted group had earlier announced that Nattawut would participate in the negotiation with the prime minister.
However, it is essential for Nattawut to remain at the main rally site -- Phan Fah Bridge -- in the center of Bangkok to take care of the red-shirted supporters.
In a related development, the prime minister's Office Minister Sathit Wongnongtoey said at a televised press conference at the 11th Infantry Regiment that it has been agreed that prior to the negotiation the protestors in front of the 11th Infantry Regiment must withdraw and return to the Phan Fah Bridge.
Shortly before 2 p.m. the red-shirted protestors started returning to their main rally site, state-run NBT Television reported.
Satit said the red-shirted protestors have agreed to withdraw from the 11th Infantry Regiment and return to their main rally site within two hours.
The government's peace-keeping operations command is located inside the 11th Infantry Regiment in Bangkok.