By Jonathan Stempel
Feb 20 (Reuters) - Warren Buffett's 2006 Cadillac attracted a high bid of $122,500, more than 10 times its market value, in a charity auction that concluded on Thursday night.
The autographed DTS sedan, with 20,310 miles (32,685 km) on the clock, was auctioned on the website Proxibid. A spokeswoman, Dana Kaufman, did not immediately identify the winner.
Proceeds from the auction will go to Girls Inc of Omaha, Nebraska, the city where Buffett runs Berkshire Hathaway Inc .
A longtime favorite charity of the 84-year-old billionaire, Girls Inc offers educational and recreational opportunities to girls in the United States and Canada. It is raising money for an $18.5 million expansion of a facility in Omaha.
Buffett's daughter, Susan, is a director of Girls Inc's national organization, and first lady Michelle Obama is honorary board chair.
Buffett will deliver the keys to his old Cadillac personally if the buyer travels to Omaha to pick them up. He replaced the car last year with a new Cadillac XTS.
A 2006 Cadillac similar to Buffett's is worth about $11,200 on the open market, according to the Kelly Blue Book.
It is common for items once owned by prominent people to sell at auction for well above market value.
In 2009, Proxibid was involved in an auction of items once owned by Ponzi schemer Bernard Madoff, including a blue satin New York Mets baseball jacket with "Madoff" embroidered on the back. Estimated to be worth $720 at most, it fetched $14,500.
Buffett previously donated his 2001 Lincoln Town Car to Girls Inc. It fetched a $73,200 high bid at auction in 2006.
Annual auctions for a steak lunch with Buffett, which benefit a San Francisco charity that serves the poor and homeless, routinely draw seven-figure sums.
(Reporting by Jonathan Stempel in New York; Editing by Tom Brown)