A masterpiece by Francis Bacon sold today for nearly £18 million (€20 million), an auction house said.

Study for a Portrait, 1953, was bought by an anonymous telephone bidder when it went under the hammer at Christie’s headquarters in central London.

The artwork had been expected to fetch somewhere in the region of £11 million but instead reached £17,961,250.

It is the second most valuable piece to be sold at a post-War and contemporary art sale at the auction house, a spokesman said.

The highest selling work in this category is Bacon’s Triptych which went for £26.3 million in February 2008.

The moody oil on canvas, which measures two metres by 1.4m, is described as “an arresting and dark study in the degradation of power”.

It was previously owned by two of Francis Bacon’s contemporaries - Rodrigo Moynihan, a pioneer of abstract painting in the 1930’s, and Louis Le Brocquy, one of Ireland’s most important painters of the 20th century.

Never previously sold at auction, the artwork has always been in private hands and was acquired by the present owner in 1984.

Meanwhile, Woman Smiling, 1958-59, a portrait by Lucian Freud sold for £4,745,250.

The only single portrait of Suzy Boyt, the mother of four of the artist’s children, it last went under the hammer in 1973 for £5,040.

Seven works from the collection of Kay Saatchi went for a total of £3,992,750 while a large scale portrait of Chairman Mao by Andy Warhol came in at £6,985,250.

The sale of 67 works is expected to make up to £77,620,000.

PA