Microsoft co-Founder Bill Gates

The wealth power of hedge fund and private equity managers is confirmed today with the publication of the of Forbes magazine's list of the 400 richest Americans in 2007, which is again headed by Microsoft co-founder Bill Gates.

The hedge fund and private equity managers make up more than half the 400.

Gates, 51, heads the list for the 14th consecutive year with a net worth of $59 billion, ahead of the $52 billion held by his friend Warren Buffett, 77, the chairman and chief executive officer of Berkshire Hathaway. Steven Cohen of SAC Capital Advisors LLC was the richest hedge fund manager with $6.8 billion, and was ranked 47th overall.

The threshold cost of joining the 25th annual Forbes 400 list increased in 2007 with the bottom rungers holding a net worth of $1.3 billion, up $300 million from last year when all the members were billionaires for the first time.

Completing the top five were Sheldon Adelson, 74, chief executive officer of Las Vegas Sands with $28 billion; Oracle Corp. Chief Executive Officer Larry Ellison, 63, with $26 billion; and Google Inc. co-founders Sergey Brin and Larry Page, each with $18 billion.

Brin and Page, both 34, replaced Microsoft co-founder Paul Allen, who dropped to No. 11 with $16.8 billion.

Kirk Kerkorian, 90, joined the top 10 at No. 7 from No. 26 with $18 billion, along with Dell founder Michael Dell, 42, with $17.2 billion in eighth place. Brothers Charles Koch, 71, and David Koch, 67, who made their money from oil and commodity investments through Koch Industries to build their $17 billion fortunes, were tied in ninth place.

Despite the subprime crisis, the list has 45 new names, mainly comprising hedge fund and private equity managers.

TPG Inc.'s David Bonderman, the chairman of Ryanair and James Coulter were joined on the list for the first time by the Carlyle Group's William Conway, Daniel D'Aniello and David Rubenstein, and Blackstone Group LP's Peter Peterson and Tony James.

Houston hedge fund manager John Arnold, 33, a former Enron Corp. trader, was the youngest member of the top 400 with wealth of $1.5 billion fortune and ranked 317, according to Forbes. The oldest member is 98-year-old John Simplot, who made his fortune in the Idaho potato business.

Thirty-nine women made the list, led by Abigail Johnson at No. 17 with $15 billion, Forbes said. Johnson's family controls Fidelity Investments, the world's largest mutual-fund company. Television star Oprah Winfrey was No. 165 with $2.5 billion.

Fifty people dropped out of the list who were included in 2006, such as Starbucks Chairman Howard Schultz. Dorrance Hill Hamilton, heir to the Campbell Soup Co. fortune, didn't make it for the first time since 1992, Forbes said.