Christie’s sold 46.9 million pounds ($75.3 million) of postwar and contemporary art at the start of Frieze week in London, as a Gerhard Richter estimated at as much as 10 million pounds failed to find a buyer at the auction.

Richter’s “Netz,” a red, yellow and green abstract painting, was sold after the auction to a private U.S. collector for 5.5 million pounds, Francis Outred, head of postwar and contemporary art, Europe, said at a news conference after last night’s sale.

The 44 works, from the Essl Collection of contemporary art in Austria, produced a total that fell within the auction house’s presale estimated range of 40 million to 56.8 million pounds.