Pumas president Victor Mahbub has confirmed they have reached an agreement with West Ham over the transfer of Pablo Barrera.
West Ham were in competition with Everton and Espanyol for Barrera, 23, but won the race after offering £4 million for the Mexico winger.
"We have just finished the negotiations for the transfer of Pablo Barrera to West Ham," Mahbub told Mediotiempo. "We and the player are satisfied with the arrangement that we have made with West Ham.
"Barrera will be signing a four-year contract and then in two or three years he will be transferred to another team. We reached a satisfactory agreement for both parties and I want to make it clear that there was no agent involved in the negotiations."
Barrera said: "I was told on Friday afternoon that my transfer to West Ham has been arranged. I'm starting to get very anxious about travelling to England so I can join my new team, know my team-mates, the stadium, the city - everything."