The unanimous vote by the board of directors to elect Mr Ruprecht to the additional role was accompanied by a similarly unanimous approval of Steven B. Dodge as the lead Independent director on the board, a role he also adopts with immediate effect.
Speaking of the changes, Mr Sovern, who retains a seat on the board, said of Mr Ruprecht: "There is no one more prepared and knowledgeable about Sotheby's and all that this company represents and what it can become, so I turn this seat over to him with great confidence in the future."
Mr Sovern became chairman of Sotheby's in February 2000. As President Emeritus of Columbia University and an accomplished lawyer, his leadership helped steer Sotheby's through the antitrust scandal. With Mr Ruprecht, he oversaw the firm's recovery to enjoy the most prosperous period since being founded almost 270 years ago.
Mr Ruprecht has been at Sotheby's for 32 years, starting as an administrator in the rug department. He became president and chief executive in February 2000 at the same time as Mr Sovern's appointment.
Prior to that, he served as managing director of Sotheby's North & South America for six years.