New York Mayor Michael Bloomberg says he will not join the race to become the next president of the US, despite rumours he would run as an independent.
Mr Bloomberg hinted he would lend his clout to someone else
In an article for the New York Times newspaper, Mr Bloomberg wrote: "I am not and will not be a candidate for president."
Mr Bloomberg said he would support a candidate who took an independent non-partisan approach.
However, he did not say whether he endorsed any of the current candidates.
The consumer advocate Ralph Nader has already announced that he will be running for president as an independent.
Thursday saw him announce that Matt Gonzalez, a former member of the San Francisco Board of Supervisors, would be his running-mate.
Texan-born Mr Gonzalez ran unsuccessfully for mayor of San Francisco as a Green Party candidate in 2003.
Senators Barack Obama and Hillary Clinton are vying for the Democratic ticket. Senator John McCain is almost certain to be the Republican candidate.
Mr Bloomberg's article brought an end to two years of speculation that he would launch a bid for the presidency.
The 66-year-old billionaire businessman said in the article that he would instead attempt to "steer the national conversation away from partisanship and toward unity; away from ideology and toward common sense".
"An independent approach really can produce progress on the most critical issues, including the economy, education, the environment, energy, infrastructure and crime. I believe... that an independent can win the presidency," he added.
It was his decision to leave the Republican Party and become an independent that first fuelled the speculation that he might be preparing to enter the presidential race.
His political experience as mayor of New York and vast personal wealth had made his candidacy seem all the more possible, says the BBC's Jonathan Beale in Washington.