An important early work by Pablo Picasso painted when he was just 19 or 20 has been put up for sale by its aristocratic Welsh owners, and is estimated to be worth around 50 million pounds.

The intention to sell Child With a Dove, a 1901 work which marked the beginning of the Spanish artist's blue period, was posted on the website of the Arts Council England which has some say over whether important works of art are allowed to be sold abroad.

The painting, depicting a child holding a dove next to a coloured ball, belongs to the Aberconway family, and was loaned to the Courtauld Gallery in London only last year, according to the Sunday Times, which first reported the intended sale.

The Arts Council England estimated the work to be worth 50 million pounds, but added that the valuation was meant only as a rough guide.

Another painting by Picasso, Nude, Green Leaves and Bust, sold for $106.5 million in 2010, the auction record for any work of art.

Auctioneer Christie's confirmed it had been instructed to find a buyer for a private sale, keeping the deal away from the attention an open auction would inevitably bring.

Keeping the painting in Britain and on public display could prove difficult given the prohibitively high price and the fact that the National Gallery, one of the country's most important collections, has run down its financial reserves in recent years.

The gallery announced last week that it had used 25 million pounds of its legacy reserves -- believed to be the majority of the total -- to help raise the 45 million pounds needed to purchase Titian's Diana and Callisto.

(Reporting by Mike Collett-White, editing by Paul Casciato)