Miro's Femmes et Oiseaux Dans La Nuit

The weak pound came to the rescue of the recession-hit art market last week as buyers from Europe, America and Asia took advantage of the relative strength of their currencies to lift London's Impressionist and modern sales above most people's expectations.

After New York's Impressionist sales in November, when 40 per cent of the art was not sold and the rest added up to just over half of what had been estimated, there was a big question as to how art should be valued. Was it all going down? And by how much? Last week's sales were the first chance for the Impressionist market to find out.

Both Sotheby's and Christie's had approached the task with caution. To restore confidence in the market, it was more important to achieve a higher percentage of sales than to attempt to challenge the record sale totals of the previous few years.

To do this, they reduced the number of lots by half compared with last February, and kept estimates as low as reasonably possible, cutting them by up to 30 per cent.

In the end, they proved that they had accurately gauged the market. The unsold rate was trimmed to just 20 per cent, and the total for the five sales held by Sotheby's and Christie's came in almost plumb on the lower estimate for the series at £126 million.

That may be the lowest total achieved since June 2005, but the selling rate, balancing the new levels of supply and demand, has rarely been bettered.

For good-quality works bought before the peak of the market, gains were being made. Degas's Petite Danseuse de Quatorze Ans, which fetched the top price of the week at £13.2 million, had cost the seller, Sir John Madejski, £5 million in 2004.

It was sold to a Japanese buyer who was fully aware of the 40 per cent fall in the value of the pound to the yen over the previous 12 months, according to Yasuaki Ishizaka of Sotheby's, who took the winning bid.

Other good results at Sotheby's were a double estimate £2 million paid by the Nahmad family of dealers, with galleries in London and New York, for a large painting by the Surrealist Joan Miró which had sold for less than one third of that price in 1999, and a Magritte painting, Souvenir de voyage, which doubled both its estimate and its previous sale price in 2000, selling to US based-art advisor Abigail Asher for £746,850.

At Christie's, a large bronze sculpture by Henry Moore also doubled its previous sale price in 2002, selling to a US collector for £2.6 million.

However, quite a few works bought at the height of the boom registered losses. A 1929 painting by Francis Picabia, who had recently sprung back into fashion, sold two years ago for £1 million, but fetched just £530,000 at Sotheby's.

At Christie's, several works that were bought a year ago were returning to the rostrum because the buyers had been unable to pay. An Expressionist portrait by Alexej Jawlensky, for example, sold for £1.9 million – £1 million less than it fetched last February.

Some experts believe that the results also underlined a waning in demand for the expensive subtleties of early Impressionist paintings.

Christie's star lot, Monet's Dans La Prairie (1876), sold for an impressive £11.2 million. But that was far short both of its estimate and of the £14.3 million it sold for in 1988 when the fashion for Impressionism was at its height.

Another early Monet from 1872, which had fetched £2.8 million in 1990, attracted no bids at the same price.

Bidders responded more to the flashier, more modern appeal of Dutch Expressionist Kees van Dongen's femmes fatales, the lively pointillism of Paul Signac, the rich colours of Emil Nolde, the surreal brushstrokes of Miró, and the bold primitivism of late Picasso – especially when prices were set at more friendly levels than before.

Sculptures, not just by Degas and Moore, but by lesser modernist figures of the early 20th century, such as Henri Laurens, and Ossip Zadkine, whose Torse de femme fetched a record £421,250, were also sought after.

One telling statistic to emerge from the select evening sales was that US buying had risen from 14 per cent of lots last year to 25 per cent of lots this year. Asian buying has also risen from two per cent to an average six per cent.

"As for prices, we know better where the market is now," said Thomas Seydoux of Christie's, as he headed off to Paris to prepare for this month's Yves Saint Laurent sale.

"There was no magic formula. The success of the sales was due to a mixture of circumstances. But without the low pound we would not have had the results we did."