The former boss of Sotheby’s was due to go on trial today accused of masterminding an international conspiracy with his counterpart at rivals Christie’s to rig commissions.

The former bosses of the world’s two largest auctioneers were yesterday formally charged with organising an ‘‘international conspiracy’’ to rig commissions.

A New York judge has given tentative approval to a £371m settlement of lawsuits over price-fixing allegations at Sotheby's and Christie's auction houses.