A deal was agreed to bring the Ecuador international from Pachuca earlier this month, pending the outcome of the hearing.
|WEST HAM LATEST
|66/1||Enner Valencia is 66/1 with bet365 to be Premier League top scorer|
"I really appreciate the welcome I've been given and I'm excited to be here," he told the club's official website.
"I've already watched and read a lot about the club to learn about it - I know the fans are really passionate and I'm really glad to have signed.
"Of course, the World Cup gives me confidence to come to Europe and I want to take and advance with this opportunity that West Ham have given to me.
"The Premier League is the top league and I have followed it in Mexico. Obviously my countryman Antonio Valencia [the Manchester United winger] has played here for a long time so it's a big step for me to come here from Mexico and I hope I can be as successful as Antonio.
"It's exciting to be here in England and London. I want to repay the club in my performances for what they are investing in me and I'm really looking forward to it."