Gazprom head Aleksei Miller told Belarusian Energy Minister Alyaksandr Ageyev about the planned change at a meeting in Moscow today.
Gazprom said Minsk would respond by the end of April.
Belarus, a close Russian ally, currently receives gas at a subsidized price of $47 per 1,000 cubic meters -- far below prices paid by customers in Europe and Ukraine.
Under a contract signed in December, Gazprom agreed to sell Belarus 21 billion cubic meters in 2006.
Belarus is heavily dependent on gas imports.
(Reuters, ITAR-TASS)