Russia's top gas enterprise, the Gazprom, will pay 2.5 billion U.S. dollars to buy half stake of a Belarusian state-owned energy company, the Itar-Tass news agency reported on Wednesday.

Gazprom's Board of Directors on Wednesday authorized the acquisition of 50 percent of Beltransgaz, owned by the Belarusian government, for 2.5 billion U.S. dollars, Itar-Tass said.

The money will be paid in four installments from 2007 to 2010, In each phase Gazprom will buy 12.5 percent of Beltransgaz shares.

Gazprom and the Belarusian government signed a protocol in 2006, pledging to create a joint gas transportation company and to supply and transport natural gas through Belarus.

The final agreement will be inked before June 1, 2007 by Gazprom and Belarus' State Property Committee, Itar-Tass said.