A 1969 triptych of portraits by British artist Francis Bacon of his friend and fellow artist Lucian Freud yesterday became the most expensive artwork ever sold at auction.

The three-picture piece was purchased by art dealer William Acquavella on behalf of an unnamed client for $142.4m (£89.6m) at Christie’s auction house, New York, following a six-minute bidding battle between seven prospective buyers.

Three Studies of Lucian Freud, which depicts Freud seated on a wooden chair against an orange background, overtakes the previous record held by Edvard Munch's The Scream (1895), which was sold to an anonymous buyer for $119,9 million (£74 million), on 2 May 2012, at Sotheby's in New York.

Francis Outred, head of Post-War and Contemporary Art at Christie's Europe, said the Bacon triptych was "a true masterpiece and one of the greatest paintings to come up for auction in a current generation".

"It marks Bacon and Freud's relationship, paying tribute to the creative and emotional kinship between the two artists," he added.