Two years ago, Louis Gonda was a billionaire. Then in September, American International Group Inc., the company from which Mr. Gonda derived the bulk of his wealth, collapsed, its shares falling from nearly $60 a share in January 2008 to less than $2.

Worth an estimated $1.4 billion according to the March 2008 issue of Forbes magazine, Mr. Gonda is selling assets. About a month ago, he put his Beverly Hills, Calif., mansion, an eight-bedroom brick Georgian he's owned for more than 20 years, on the market for $42 million. Within...