The Hammers boss has already ironed out a loan deal for Chilean international Luis Jimenez, and has supplemented the ranks of the Boleyn Ground outfit with Diamanti, a striker comes with a high regard scoring 18 goals in 37 league and cup matches last season.
West Ham's recruitment drive has also seen Herita Ilunga, Radoslav Kovac, Fabio Daprela and Frank Nouble sign.
The 26-year-old penned a five-year deal, and is quoted by the club's official website as saying, "I am very happy to be at West Ham United and to get the chance to play for Gianfranco Zola. This is a big club and I want to give everything for the supporters."He continued, "I chose West Ham because the club has the tradition of playing great football. Also because the West Ham fans are really passionate and that is the way I am."
Alan Dawson, Goal.com