The government delegation to the talks in Cairo is being led by federal minister Nafie Ali Nafie. The opposition delegation is led by Abd al-Rahman Said.
National Democratic Alliance (NDA) leader Muhammad Uthman al-Mirghani hosted a banquet at his house for members of both delegations.
Sudanese sources said the gathering highlighted the positive climate under which the talks were being held.
The ongoing negotiations coincided with a fresh round of talks being held in the Nigerian capital of Abuja between the Sudanese Government and the rebels over the crisis in Darfur.
Meanwhile, the British minister of state for African affairs, Chris Mullin, has blamed Khartoum for its failure to control militias, including the Janjawid, in the Darfur region.
"The Khartoum government has not yet reined in the Janjawid and local militias. It has not done enough yet," Mullin said.
The British minister, however, said Khartoum has eased restrictions on the flow of humanitarian aid into the strife-torn region, in line with demands made by the United Nations.