The forward signed for an undisclosed fee but British media said it was a total of 32 million euros.

"Atalanta B.C. would like to extend a warm welcome to Gianluca and wish him the best of luck in his future personal and team projects as a Nerazzurro," the Italian club said in a statement.

Scamacca played one season for the Hammers, who finished 14th in the Premier League, netting eight goals in 27 appearances, including five in West Ham's run to the Europa Conference League title - their first major trophy in 43 years.

The transfer comes after Manchester United signed Atalanta's Denmark striker Rasmus Hojlund on Saturday.

West Ham last month sold England midfielder Declan Rice to Arsenal for a reported 105 million pounds.