Sales of art at Christie's have slumped to £2.1bn in the first half of this year, down 27 per cent from last year as the global art market contracts. The London-based auction house, which is celebrating its 250th anniversary, said there was a fall in the number of works priced above £20m at auction. Despite that, smaller ticket sales and transactions conducted online strengthened: there were 36 per cent more new buyers of works between £1m and £5m, and e-commerce jumped 96 per cent. Christie's, owned by French billionaire François Pinault, is coming off its second-best year ever, buoyed by online bidding, curated auctions — which span classifications and time periods — and a group of new buyers. Its rival Sotheby's said sales totalled $2.4bn this year through to June 30, though that does not include private sales, which are recorded in Christie's figures. For Sotheby's this is down from $3.1bn in the same period last year. Sales in the global art market declined seven per cent over the course of 2015 to $63.8bn, according to the industry benchmark Tefaf Art Market Report. After years of rising prices lured in new buyers, volatility in financial markets last year started to cool demand. For top lots, prices continued to soar, while other items failed to sell. That spurred concerns that the market was wobbling, making collectors less excited to part with their treasures. Where before auction houses had extended generous guarantees, as their competition to lure consignors to market intensified, they have now cut these back, scaled down the size of the sales, and are trimming staff. "Our total focus is on curating sales to meet collectors' demands while satisfying our sellers by ensuring the highest possible number of bidders on each lot," said Patricia Barbizet, Christie's chief executive. "We continue to bring to our consignors the broadest reach of international buyers, which increase season by season." The market is increasingly polarised, with most of the value concentrated in the postwar and contemporary and modern categories, and in sales at the highest price levels, according to Tefaf's report. Christie's also noted that "demand for masterpieces by top collectors continues", with 88 per cent of all works costing more than £5m being sold. This year Christie's has set new auction records for artists, including Jean-Michel Basquiat, Henry Moore and Frida Kahlo. In the first half of the year, sales in America totalled £729.8m, down by almost half from the same period last year, Christie's said. Sales in Europe, the Middle East, Russia and India shrank 12 per cent to £736.5m, while Hong Kong contracted 11 per cent to £256.5m. Christie's has put a focus on its curated auctions, with May's cheekily titled "Bound to Fail" sale managing to surpass the tempered expectations set for it, with all but one of the 39 works selling. It brought in $67m excluding fees, beating presale estimates. Yet, this was weak compared with 2015's curated sale, which drew in $611m. Christie's says that over the past 16 months it has tweaked its calendar, platforms and less-expensive offerings to help attract new buyers. It has also beefed up its First Open sales, which target lower price ranges. Sotheby's, which announces its first-half results in August, is set to sell art and furniture owned by the late musician David Bowie in November.