Serbia's government on Tuesday approved a strategic deal for long-term gas supplies from Russia through a branch of the proposed South Stream pipeline.
Velimir Ilic, Serbian infrastructure minister, said he would sign the intergovernmental agreement in Moscow on Saturday.
The Belgrade government on Tuesday adopted a draft agreement on energy cooperation with Russia, under which Serbia would be included in the South Stream gas pipeline project to take Russian gas to Europe under the Black Sea.
In return Serbia would sell a majority of NIS, the state oil monopoly, to Gazprom's oil arm, Gazprom Neft, for a price still under negotiation.
Vojislav Kostunica, Serbian prime minister, said the agreement, which averts competing bids for NIS from other foreign energy companies, would be "a basis for more talks" between Gazprom and Serbian gas officials.
Mr Kostunica wants stronger economic ties with Russia, Serbia's ally in the Kosovo dispute. Other cabinet members had dismissed Gazprom's first offer last month of €400m ($586m) cash and €500m investment as far too cheap. But the cabinet got behind the deal in the hope that Mr Kostunica would support Boris Tadic, the pro-European Union president who faces a tough run-off election round against a pro-Russian nationalist challenger on February 3.
Belgrade, which gets 90 per cent of its gas from Russia, sees the South Stream branch into Serbia as a way to secure cheaper power and faster economic growth.