What am I bid?... Sotheby's up for sale

Sotheby's, the venerable auction house, is looking for a buyer or a merger after its principal shareholder, Alfred Taubman, who was recently convicted in a price-fixing scandal, said he was planning to sell his majority stake in the company. Under a deal struck with Taubman, the firm has 90 days to find a new owner or partner. After that, Taubman will be free to sell his shares wherever he pleases.

"This is an important day for Sotheby's," said Bill Ruprecht, its chief executive officer. He predicted the process of passing control of the company would take "at least several months".

In April, Taubman, 78, was sentenced to a year and a day in jail and fined $7.5m (£5m)for his part in a six-year price-fixing scam with the rival auctioneers Christie's. Pending his appeal, he is to begin his term on 1 August.

Sotheby's, founded by Samuel Baker in London in 1744, was bought by Taubman, a shopping mall tycoon, in 1983 and taken public in 1988. It has been hard-hit by the scandal, although Christie's won immunity by co-operating with investigators.

The task of marrying the firm to a new owner goes to three investment banks, Goldman Sachs, for Taubman, and JP Morgan and Morgan Stanley for Sotheby's. Taubman owns 13.2m Sotheby's shares, equivalent to a voting majority of about 62.9 per cent. His stake is thought to be worth at least £100m.

Mr Ruprecht conceded that a new suitor could buy either Taubman's shares, or alternatively, the entire company. That also opens the possibility of Sotheby's being broken up. He refused to say whether contacts had been made with possible buyers.

Asked to comment on whether eBay, the online auction company with which Sotheby's already has ties, might buy the firm, Mr Ruprecht said only: "I wouldn't rule anybody out and I wouldn't rule anybody in."

Taubman's former CEO at Sotheby's, Diana Brooks, was given just six-months' house detention in Manhattan for testifying against her former boss.

Christie's has been controlled for four years by François Pinault, a French luxury-goods magnate. The US prosecutors also accused the former chairman, Sir Anthony Tennant, with engaging in price-fixing. Sir Anthony, a leading City figure and symbol of patrician authority, refused to go to the US to stand trial. He cannot be extradited on this charge.