Radoslav Kovac from Spartak Moscow has signed a permanent deal with West Ham after spending last season on loan at Upton Park.
"I'm delighted to be back," the 29 year old told the West Ham website.
"I enjoyed my time here last season and I am very happy to get the chance to come back and compete for a place at West Ham.
"It is great that it is permanent deal and that it is all sorted out."
Boss Gianfranco Zola said: "He is a good player for us. He has got experience, he has got charisma, a good personality and he will be an important player for us."