UBS sold its nearly 1 million-square-foot office building at 135 West 50th Street in Manhattan for $8.5 million, a 97% drop from its 2006 purchase price of $332.5 million. The sale, conducted on Ten-X, an online auction platform, followed a two-day bidding process that began with a $7.5 million starting bid. The aging, Class A building is only 35% occupied despite a $76 million renovation. UBS retains responsibility for an $800,000 monthly ground lease, set to expire in 2123. The new owner may choose to redevelop or convert the property for residential use.