MILAN, Italy (Reuters) -- AS Roma have signed 19-year-old Erik Lamela, one of Argentina's brightest prospects, the president of River Plate told Italian media on Saturday.

"Lamela is an AS Roma player," former Argentina captain Daniel Passarella told reporters after meeting AS Roma officials. All that remains to do is to register the contract with the federation."

Italian media said Roma would pay River Plate 12 million euros for the player who made his Argentina debut in a friendly against Paraguay in May. He has been offered a five-year contract.

Lamela, a tall, elegant, left-footed player, made an impact last year with his performance in the derby against Boca Juniors and had attracted interest from Barcelona several years ago.

Despite his pedigree, Lamela, who made his professional debut two years ago, was part of the River Plate team which was humiliatingly relegated to the Argentine second division this season.

Lamela had already told his fans about the move on Twitter.

AS Roma, who finished sixth last season to qualify for the Europa League, last month appointed former Barcelona and Spain player Luis Enrique as coach.

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