But hopes that the announcement would signal an end to fighting among rival factions were dashed as a more than week-long battle intensified for control of Tripoli airport.
"Monday, August 4 has been set as the date for the transfer of power ... To the elected chamber," the GNC said in a statement signed by its speaker, Nuri Abu Sahmein.
The handover is to take place within two weeks as specified of Monday's publication of the election results.
In Tripoli, there was no sign of a ceasefire yesterday between the rival factions fighting around the capital's airport.
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A fresh appeal from Libya's transitional government for a humanitarian truce fell on deaf ears, with explosions heard from the centre of the capital and plumes of smoke clearly visible.
"Rockets fell on several homes and many families have fled the fighting," local resident Mohamed Farhat, whose home on the airport road was hit by a missile, told AFP.
The clashes, the most violent in Libya since Kadhafi's overthrow, started with an assault on the airport by a coalition of armed groups, mainly Islamists, which has since been backed by factions from the eastern town of Misrata.
The assailants are battling to flush out fellow former rebels from Zintan, southwest of the capital, who have controlled the airport for the past three years.
The battle has caused serious damage at the airport and at least a dozen aircraft have been destroyed or partially destroyed by fire.
Viewed by their opponents as the armed wing of Libya's liberal movement, the Zintan brigades also hold several other strategic military and civil sites in the southern districts of Tripoli.