U.S. duo Sullivan & Cromwell and Ropes & Gray are among the firms advising on the sale of iconic London auction house Sotheby's for $3.7 billion.

French-Israeli businessman Patrick Drahi is set to take over the business via his investment vehicle BidFair.

If successful, the deal will see Sotheby's return to private ownership after 31 years as a public company traded on the New York Stock Exchange.

Drahi is the founder of multinational telecommunications company Altice, listed on the Amsterdam stock exchange.

Sullivan & Cromwell is advising Sotheby's on its sale. According to a source familiar with the matter, the Sullivan & Cromwell team advising includes U.S.-based M&A partner Melissa Sawyer and corporate finance partner John Mead.

Ropes & Gray is advising BidFair USA on its financing of the deal, fielding a London-based team. London finance partner Michael Kazakevich and derivatives and commodities partner Anna Lawry are among the advisers.

Fellow U.S. firm Hughes Hubbard & Reed is advising BidFair USA on the corporate aspects of the deal, with its team led by deputy chairman and M&A partner Ken Lefkowitz.