Forbes: Blazers' Paul Allen Is Richest American Owner In Professional Sports

Portland Trail Blazers owner Paul Allen ranks No. 26 on the Forbes 400 ranking of the richest Americans. Allen is worth an estimated $15.8 billion.

Microsoft cofounder Paul Allen owns only an estimated $2 billion in the software outfit's stock but is still bullish on technology. His Vulcan group just opened a venture capital office in Silicon Valley, investing in online retailer Gilt Groupe and a cloud-software firm. In late 2012 he sold a 12-building campus in Seattle to Amazon, which was leasing the space, for $1.15 billion. He owns the Seattle Seahawks and Portland Trailblazers. With his band, The Underthinkers, he just released country-rock album Everywhere At Once. Allen gave away $113 million so far in 2013, including a gift to Allen Institute for Brain Science and $1 million to the Jane Goodall Institute for great ape conservation efforts in the Congo. His aviation venture called Stratolaunch is still aiming for a 2016 test flight of what would be the world's largest airplane, one designed to launch satellites from mid-air into low-earth orbit.

Allen's Microsoft co-founder, Bill Gates, again ranks No. 1 overall on the list with an estimated net worth of $72 billion.

Allen is the top-ranked professional sports owner on the list. Darren Rovell of ESPN.com runs down the other NBA owners on this latest list.

The richest sports team owner is Microsoft co-founder Paul Allen of the Portland Trail Blazers and the Seattle Seahawks. ... The richest NBA owner [besides Allen] is Orlando Magic owner Rich DeVos, who comes in at No. 60 on the list with a net worth of $6.8 billion.

There are 12 other NBA owners on the list, including Kroenke (Nuggets), Micky Arison (Heat, $5.9 billion), Dan Gilbert (Cavaliers, $3.9 billion), Charles Dolan (Knicks, $3.3 billion), Tom Gores (Pistons, $2.7 billion), Mark Cuban (Mavericks $2.5 billion), Josh Harris (Sixers, $2.5 billion), Robert Pera (Grizzlies, $1.95 billion), Herb Simon (Pacers, $1.95 billion), Donald Sterling (Clippers, $1.9 billion), Glen Taylor (Timberwolves, $1.7 billion) and Benson (Pelicans).

Last year, Allen ranked No. 20 on the list with an estimated net worth of $15 billion.

Back in March, Allen ranked tied for No. 53 on a list of the world's richest billionaires with an estimated net worth of $15 billion. At the time, he moved past Brooklyn Nets owner Mikhail Prokhorov, who ranked No. 69. with an estimated net worth of $13 billion.

-- Ben Golliver | benjamin.golliver@gmail.com | Twitter