Russian metals tycoon and US basketball team owner Mikhail Prokhorov has said that he intends to challenge Vladimir Putin in next year's presidential elections.
"I have made the most serious decision of my life. I am running for president," Prokhorov told reporters on Monday.
The owner of NBA's New Jersey Nets basketball team had previously made a short-lived effort to challenge Putin's United Russia party in this month's parliamentary elections.
He later resigned from his own party following an internal power struggle that he blamed on the Kremlin. The Right Cause party finished with less than one per cent of the vote.
His bid for the presidency comes after unprecedented nationwide protests against Putin, the prime minister, and his party following the polls. Putin's United Russia lost about 20 per cent of its seats, although it did retain a narrow majority.
Prokhorov, the chairman of the Polyus Gold metal mining firm, has been consistently ranked as one of Russia's top five billionaires by Forbes magazine and was estimated to have a fortune of $18 billion in 2010.
At the press conference where he announced his presidency bid, he refrained from criticising Putin or his protege Dmitry Medvedev, the country's president, but said that Russian "society is waking up".
"Those authorities who will fail to establish a dialogue with society will have to go," he said.
It is as yet unclear how effective a challenger Prokhorov would be against Putin. His wealth and playboy reputation may count against him, with voters historically loathe to support those who have thrived economically while millions of Russians scraped together a living in the years since the Soviet Union collapsed.