An equestrian painting by artist George Stubbs is expected to sell for up to £15m at auction later this year.

The work, Brood Mares and Foals, goes under the hammer at Sotherby’s in London on 8 December. The auctioneers believe it will fetch between £10m-£15m.

The painting, which was finished in 1767, was shown at two exhibitions in 1978 but only once since — in 2005 in a show dedicated to Stubbs. The painting has been in the Earl of Macclesfield’s family, who are not putting it up for sale.

A spokesman for Sotherby’s said: “It is an immense pleasure to be offering this exceptionally fine work by Stubbs, which is instantly recognisable as one of his most beautiful and iconic compositions.”

The current auction record for Stubbs was set by his Portrait of the Royal Tiger, which sold in 1995 for £3,191,500.