One of David Hockney's most famous works was sold at Sotheby's last night for a record £2.9m, providing the latest evidence of an extraordinary boom in London's art market.

The sale of The Splash sealed an astonishing three days for the British art market during which all known sales records for the capital have been broken. According to estimates, by tomorrow the world's big-spending art lovers will have spent £260m at London's annual week of high-profile sales.

The strong sales are being attributed to a weak dollar and a new crop of wealthy buyers from Russia and the Middle and Far East who have injected life into a market that some in the capital feared was fading.

Big-name Impressionist and modernist works, including a £16.3m Modigliani, helped Sotheby's take a total of £109.3m for its series of sales - the highest for any auctions held in London. Its arch-rival Christie's took £87m at its main evening sale on Tuesday, boosted by an Egon Schiele which went for £11.8m, a record for its UK house. The Hockney sale at Sotheby's trounced the previous record for his work set at Christie's New York in May when A Neat Lawn, 1967 was sold for £1.9m.

There were similar scenes across the Atlantic in New York on Monday, where Ronald Lauder was reported to have paid a record-breaking £73m for a Gustav Klimt.

But it is the London week of sales that was attracting attention in the art world yesterday. Fine art specialists saidthe arrival of the Russians and Asians was key. In the past, Americans took two-fifths of the art on offer in London, matched by the Europeans, leaving a fifth to the rest of the world. The Russians are more conspicuous among the new collectors but Asian buyers are just as assiduous if more subtle, often using agents to bid.

Helena Newman, a board director of Sotheby's Europe, said: "Five or six years ago, people were saying that Impressionists were dead and there's no market and everyone wants contemporary art. But what this showed was that, when you have Impressionist images of fabulous quality, then the buyers come out. A lot of American collectors who haven't bid in recent sales came back in because there might not ever be another opportunity to buy works of this quality. In the room bidding [on Monday] there were more people sitting there than I have ever seen before, including a lot of new people - and a few who had never been at auctions before."

Indeed, the total of the week's sales at London could exceed the estimate. Another sale at Christie's yesterday took some £12.4m and the conservative pre-sale estimate for last night's contemporary sale at Sotheby's, where Bridget Riley's 1966 Untitled (Diagonal Curve) sold for a record £1.18m, was £22m.

And at least another £21m is expected to be taken by Christie's at its contemporary sale tonight, where the highlight is a previously unseen Francis Bacon triptych which has been owned by a friend of the artist for the past 24 years. Remaining day sales at the two auction houses have a total estimate of at least £22m.

Part of the buzz around London is the result of a self-fulfilling prophesy. A strong market is attracting some of the finest work in years. And brilliant work makes record prices - attracting further art for sale.

The strength of the market has even encouraged some owners to sell works which, in some cases, have been in families for generations, including recently restituted works looted by the Nazis.

The weak dollar has further persuaded certain American collectors to sell for sterling in London rather than New York. This means that London auction houses this week secured quality works that might have been expected to sell in America only a few years ago. Jussi Pylkkanen, president of Christie's Europe, said that London was riding "the crest of a wave of enthusiasm" that started with fierce bidding at auctions in New York in May followed by strong interest in the recent international art fair in the Swiss city of Basel.

"A lot of people missed a huge number of works they had wanted to buy [in New York and Basel] and London was the final destination of the summer season," he said.

They arrived eager to buy - but discerning. In many cases, a Picasso, a Warhol and an Impressionist is what they wanted as the mainstay of a new collection. And whereas the previous boom at the end of the 1980s included a great deal of borrowed money and speculation by finance houses, the market today, with its mix of new and established buyers, seems solid. "It's not frothy," Mr Pylkkanen said.

Hockney said: "The Splash itself is painted with small brushes and little lines; it took me about two weeks to paint The Splash. I loved the idea, first of all, of painting like Leonardo, all his studies of water, swirling things. And I loved the idea of painting this thing that lasts for two seconds; it takes me two weeks to paint this event that lasts for two seconds. Everyone knows a splash can't be frozen in time, so when you see it like that in a painting it's even more striking than in a photograph."

Cash for canvas

Sotheby's

Amedeo Modigliani's Jeanne Hebuterne was sold for £16,360,000 to an anonymous buyer.

Pablo Picasso's Le Pientre et Son Modele was sold for £7,400,000 to an unknown trade buyer.

Edgar Degas' La Sortie du Bain was bought for £6,728,000 as a private European purchase.

Pierre-Auguste Renoir's Femmes dans un Jardin went for £4,936,000 to a private buyer.

Pierre Bonnard's Place Clichy was sold to an anonymous buyer for £4,152,000.

Lyonel Feininger's Angler with Blue Fish II was sold to an anonymous buyer for £4,152,000.

Edouard Vuillard's Le Pot de Gres was sold for £4,040,000 to an anonymous buyer.

Henry Moore's Large Four-Piece Reclining Figure was sold for £3,368,000 to an anonymous buyer.

Kees Van Dongen's Portrait de Fernande was sold to a private buyer for £2,920,000.

David Hockney's The Splash was sold for £2,920,000.

Christie's

Egon Shiele's Herbstsonne went to a private buyer on Tuesday for £11,768,000.

Pablo Picasso's Homme à la Pipe Assis et Amour was sold for £4,264,000 to a European trade buyer.

Paul Cézanne's Maisons dans la Verdure went for £4,152,000 to an American private buyer.

Pierre-Auguste Renoir's L'éte: Jeune Femme dans un Champ Fleuri was sold for £3,816,000 to a private buyer.

Amedeo Modigliani's Homme Assis sur Fond Orange went for £3,684,000 to a European trade buyer.

Pablo Picasso's Au Moulin Rouge (Le Divan Japonais) went for £3,592,00 to an anonymous buyer.

Amedeo Modigliani's Le Buste Rouge (Cariatide) was sold for £3,480,000 to a European trade buyer.

Pablo Picasso's Tete d'Homme went to a private European buyer for £3,480,000.

Pablo Picasso's Femme dans un Fauteuil, Les Bras Croisés was sold for £3,032,000 to a private buyer.

Vincent van Gogh's Still Life: Vase with Gladioli and Lilacs went for £2,248,000 to a private buyer.