Britain has placed a temporary export ban on a key Picasso painting which had been on loan to a public gallery since 1974 before its aristocratic owners decided to put it up for sale.

"Child with a Dove" was painted in 1901 and marked the beginning of the Spanish artist's "blue period." It has been valued at 50 million pounds ($80 million).

Culture Minister Ed Vaizey said on Friday he was preventing the work from leaving the country until December 16, and, if a "serious" attempt to meet the asking price was made by a private buyer or institution outside Britain, until June 16, 2013.

"This will provide a last chance to raise the money to keep the painting in the United Kingdom," the Culture Ministry said in a statement.

Works can be bought by public institutions for significantly less than the guide price through private sale arrangements that involve sharing tax advantages between the two parties.

Vaizey based his decision on recommendations by the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest which is administered by Arts Council England.

The committee decided that the painting, which was placed on long-term loan to the National Gallery in London in 1974 and remained there until 2010, was sufficiently important and closely connected with Britain to justify the export deferral.

"'Child with a Dove' is a much-loved painting whose iconic status, together with its long history in British collections - latterly on loan to public galleries - make it of outstanding importance to our national heritage," reviewing committee member Aidan Weston-Lewis said.

Earlier this month the Ashmolean Museum in Oxford announced that Edouard Manet's "Portrait of Mademoiselle Claus" would go on show after it was bought for 7.8 million pounds ($12.5 million), compared with the original sale price of 28.35 million ($45.4 million).

The Picasso work depicts a child holding a dove next to a colored ball, and belongs to the Aberconway family. In March, auctioneer Christie's confirmed it had been instructed to find a buyer for a private sale.

Another painting by Picasso, "Nude, Green Leaves and Bust," fetched $106.5 million in 2010, an auction record for a work of art. It has since been surpassed by Edvard Munch's "The Scream," sold at Sotheby's in May for $120 million.

1 pound = $1.60

(Reporting by Mike Collett-White; Editing by Sandra Maler)