I fell in love with her even though she's meant to be 62

Robert Noortman

The painting was part of a sale of the huge collection of the late Baroness Batsheva de Rothschild.

Mr Noortman, who owns a gallery at Maastricht, said: "You can tell that the woman in this painting must have been someone Rembrandt really liked, because it is so intimate.

"There is such feeling in it that you fall in love with the old lady just looking at it. I fell in love with her even though she's meant to be 62 - and my wife didn't even mind."

The portrait is thought to be one of Rembrandt's early works

Portrait of a Lady, signed and dated by Rembrandt in 1632, had been part of the Rothschild collection for three generations.

A major work by the 17th Century Venetian artist Canaletto was also sold for �7.7m. The painting, Campo Santi Giovanni e Paolo, had been expected to fetch around �4m.

A tiny painting by El Greco also surprised auctioneers by selling for �1.3m.

Rembrandt's 'friend'

The panel, called The Flight Into Egypt, measures just six-and-a-quarter by eight-and-a-half inches.

The woman portrayed in the Portrait of a Lady is believed to be a friend of Rembrandt, a 62-year-old called Aeltje Uylenburgh.

She was the wife of a Calvinist clergyman, Johannes Sylvius, who also had close contact with the painter.

The clergyman vouched for Rembrandt when he got married and Christened the artist's second child, his daughter Cornelia, in 1638.

Mr Noortman said: "It is the best Rembrandt to come up at auction for decades and he was one of our greatest painters, so I am very happy.

"I knew it was going to go for more than Christie's thought, but it's only money."

The painting sold for �18m plus �1,803,000 and �315,000 in VAT.

'Significant auction event'

A Christie's spokesman said the collection, led by the Rembrandt, also includes Islamic and Venetian glass as well as other decorative objects and porcelain, including "a superb group of Renaissance style jewellery".

The sale was described as "a major highlight of the international sales calendar" this autumn.

Lord Hindlip, chairman of Christie's, said: "The Rothschild name is synonymous with the very best and broadest collecting.

Art collector

"The appearance of these works, led by a particularly important group of Old Master paintings, marks a significant auction event."

The Baroness Batsheva de Rothschild, who died last year, was born in London, in 1914, but came from the French arm of the great dynastic banking family.

In true Rothschild style the Baroness bought and collected works of art and inherited many pieces from her grandfather, Baron Alphonse de Rothschild, who was one of the 19th Century's greatest collectors.

Her impressionist and modern pictures and drawings are to be sold in February 2001.