The 49-year-old Chubais, one of Russia's best-known figures, came to prominence as the architect of post-Soviet economic reforms under which two dozen ``oligarchs'' acquired vast wealth while ordinary people suffered a huge slump in living standards.

He is chief executive of Unified Energy System and the prime mover behind reforms to introduce competition to the power sector of the world's largest country.

Chubais said he knew who wanted him dead, but did not name them, and refused to be intimidated. ``Everything that I have done - in reforming the country's power sector, and in uniting the country's democratic parties - I will continue doing, with twice the strength.''

Company officials said Chubais arrived at his Moscow office unscathed after the assassination attempt. Police said he had been traveling along a wooded section of the Minsk Highway, west of Moscow, when he came under attack at 9:30am.

The armored BMW in which Chubais was traveling left the scene immediately, while security guards travelling in a Mitsubishi Lancer jumped out and returned fire at two assailants. Both escaped.

Investigators found a large crater at the side of the two-way highway running through forest, with bullet cartridges, already tagged by investigators, lying on the icy ground.

Chubais, a former leader of the Union of Right Forces party, quit politics in 1998 to take the helm at UES.

He was ranked in a recent opinion poll as Russia's most influential businessman.

The tough-talking economist was a leading member of the ``young reformers'' close to Yegor Gaidar when he was prime minister.

Chubais was also the architect of a 1990s privatization drive that led to vast wealth being concentrated in very few hands.

Critics accused Chubais of launching an era of ``wild capitalism'' when gangland-style killings became a widely used method to acquire control of businesses.

Only last November, Chubais told a newspaper he had been the target of three assassination attempts for ``purely political motives'' and that he ``was hated because I `had sold Russia.'''

Chubais ran former Boris Yeltsin's successful presidential re-election campaign in 1996 - surviving allegations he ran an illegal election slush fund - and then quit politics to go into business just as Russia's 1998 financial crisis hit.

He now heads a company with annual revenues of US$21.6 billion (HK$168.5 billion) and a market capitalisation of US$12.6 billion, making it Russia's seventh-largest.

Former reformist ally Boris Nemtsov believes the attack on Chubais was politically motivated.

``For me, it is completely obvious that this assassination attempt has a political character and is not connected to the reforms of UES,'' Nemtsov said.

Analysts said that transforming UES from a Soviet-era monolith into a market-sharp firm capable of promoting Russia's economic development cannot happen without Chubais.