New York Mayor Michael Bloomberg left the Republican Party on Tuesday and became an independent, a move seen by some as prelude to a bid for the White House in 2008.

Bloomberg, a billionaire, switched to the Republican Party from a lifelong Democrat in 2001 for his first campaign for mayor.

He said Tuesday that the latest switch did not mean he was running for president.

"Although my plans for the future haven't changed, I believe this brings my affiliation into alignment with how I have led and will continue to lead our city," said Bloomberg, who has an estimated worth of 5 billion dollars.

Despite Bloomberg's repeated promise to leave politics after his mayoral term ends in 2009, there has been speculation that the 65-year-old mayor will run as an independent in 2008.

Editor: Yan