A three-canvas painting by Francis Bacon has sold in London for 26.34 million pounds ($57.87 million), narrowly missing out on a record for the artist at auction.The figurative artist's Triptych 1974-1977, which had been in private hands, was described by auction house Christie's as "the most important work by Francis Bacon to ever appear at auction".It was expected to fetch upwards of 25 million pounds. Despite beating this figure, the final price fell just short of the record for a Bacon sold at auction.Study from Innocent X (1962) was sold in May last year for 26.58 million pounds, and also represents the record for any work by a British or Irish artist sold at auction.The record for any post-war painting sold at auction is held by Mark Rothko's Yellow, Pink, Lavender on Rose, which fetched $US72.8 million at a sale in New York in May.Dublin-born Bacon, who died in 1992, created Triptych 1974-1977 on the eve of a major exhibition of his work in New York in 1974. It is a response to the suicide of his lover, George Dyer, in a Paris hotel three years earlier. It shows sequential images of dark, ominous umbrellas and Bacon's lover struggling on a near-deserted beach. Many of Bacon's works after this time were preoccupied with Dyer and the tragic manner of his death.Last night's sale was part of a bumper week of auctions of impressionist, modern, post-war and contemporary works by some of the world's most famous artists by Christie's and rival Sotheby's.