The announcement came several months after the movement, backed by some militias and local tribes, declared the eastern half of Libya to be an autonomous state, named Barqa, claiming broad self-rule powers and control over resources.
The central government in Tripoli had rejected the declaration. It had no immediate comments today.
Advocates of the self-rule in the east, who long has complained about discrimination by the government in the capital Tripoli, have been pushing for the reviving the system maintained under King Idris in 1951.
Opponents fear a declaration of autonomy could be the first step toward the outright division of the country, particularly with the turmoil that struck in the aftermath of the fall of longtime dictator Moammar Gadhafi.
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The tension between the central government and eastern militias and tribal leaders has already disrupted the exports of oil. Eastern militias earlier seized control of oil exporting terminals, sending production plunging from 1.4 million barrels a day to around 600,000, robbing the country of its main revenue source.
"The aim of the regional government is to share resources in a better fashion, and to end the centralized system adopted by the authorities in Tripoli," al-Barassi said at a news conference in the northeastern town of Ajdabiya.
He dismissed accusations that the movement's leaders are only seeking to take control of the region's oil resources. "We only want Barqa's share according to the 1951 constitution," he said.