Gazprom and SUEK signed a letter of intent to form a joint venture Thursday. The natural gas monopoly will control 50% plus one share in the new company and SUEK will hold 50% minus one share.
"I only know about this deal from the media and I think it is a big victory for SUEK shareholders and a big mistake on the part of the government - unfortunately, not the first one," Chubais, CEO of Unified Energy System, said at a telephone conference. He declined to elaborate.
A former first deputy prime minister under President Boris Yeltsin, Chubais was a pioneer of the controversial privatization campaign in Russia in the 1990s, which produced a small number of now-famous Russian oligarchs, but left much of the country impoverished.
His position came under threat when President Vladimir Putin came to power in 2000 and launched a campaign against tycoons, the most high-profile case being the imprisonment of Yukos founder Mikhail Khodorkovsky.
Despite public expectations, Russia's top electricity official retained his post after a blackout in Moscow in May 2005 that left several districts of the capital and neighboring areas without power for two days, causing substantial economic damage.
Chubais survived an attempt on his life in March 2005.