NEW YORK — Mayor Michael Bloomberg is apparently even richer than anyone realized. Forbes magazine's annual list of richest Americans is estimating his wealth at twice the number it gave last year, vaulting him to the rank of 25 with a fortune estimated at $11.5 billion.
Last year, he was at a mere 40th place, with a net worth valued at $5.5 billion. The difference shows how hard it has been to guess the wealth of the mayor and potential presidential candidate.
He retains 68 percent ownership of his company, Bloomberg LP, but it is privately held and does not release much financial data. Fortune magazine estimated in an article this year that the company's 2006 operating profits were $1.5 billion before taxes.
Matthew Miller, editor of the Forbes list, said the change in Bloomberg's personal value was based on the magazine's estimate of his company's worth. Large media deals like Thomson's purchase of Reuters, valued at nearly $18 billion, and Rupert Murdoch's $5 billion buy of Dow Jones & Co. helped the magazine pinpoint Bloomberg, Miller said.
"We came up with a number that was much higher than last year based on current market conditions and what people are paying for media companies," Miller said. He would not say how much the magazine calculated Bloomberg's company is worth; other estimates have topped $20 billion.
Bloomberg said last year that although he had been approached by buyers, he had decided not to sell at that time. Bloomberg conceded, however, that "there will come a day _ I hope later rather than sooner _ when I or my estate will have to sell."
Bloomberg is often mentioned as a potential third-party presidential candidate, in large part because he has enough wealth to finance an elaborate campaign without raising money.
He insists he will not run and plans to focus full time on philanthropy. Each year he gives away more and more of his money to charity; in 2006, the total was $165 million to more than 1,000 recipients.
The mayor's spokesman declined to comment about Bloomberg's new Forbes rank.