Christie's auction house says a piece by John Constable has sold for 22.4 million pounds, setting a record price for the English romantic painter at auction.

"The Lock," finished in 1824, is one of six paintings from Constable's celebrated series depicting the Stour Valley. The painting, which came from the collection of Baroness Carmen Thyssen-Bornemisza, was the last of the series to remain in private hands, according to Christie's.

It said the piece - which it said was "remarkable for its excellent state of preservation" - was sold Tuesday night in London to an anonymous bidder over the phone.

The auction house had estimated the piece would fetch between 20 and 25 million pounds.