Francis Bacon painting "Man in Blue VI"

A rare portrait by Francis Bacon which was expected to fetch up to £6 million has failed to sell at auction amid fears that the recession is hitting collectors.

The painter's Man in Blue VI was one of a series of seven paintings he completed in the spring of 1954.

It had been estimated to fetch a price of between £4m and £6m when it went under the hammer at Christie's auction house in London on Wednesday night.

However, bidders failed to reach the asking price and the painting was returned to the vendor.

The work reveals a smartly dressed man whose features seem obscured, seated at the centre of a cavernous dark canvas.

The painting is unusual in that the artist appears to have painted the sitter from life as opposed to using a photograph, which was Bacon's typical method.

The sitter is an unknown man who Bacon is thought to have met at the Imperial Hotel in Henley-upon-Thames, where the painter was living at the time.

Despite the disappointment of the Bacon picture failing to sell, Christie's reported that 79 per cent of the other pieces on offer in its Post-War and Contemporary art sale had been sold.

The auction house blamed the style of the painting itself rather than its price tag in the economic gloom for disinterest in the sale.

A Christie's spokesman said: "I don't think we can blame the credit crunch for the Bacon picture not selling. It was quite an academic piece.

"Collectors still have that liquidity in the market.

"There was a lot of interest in the painting in the run up to the sale and there has been immediately after."

He said it was possible that the painting may now be subject to a private sale.