It was thought former manager Steve Bruce would try to hicjack the move but 'Bobby' saw enough to gleen light the move.
The manager said of his new player: "He is a powerful figure in midfield, who can sit in front of the back four and destroy attacks, or can also come forward and score.
"He is a player the club has worked really hard to secure these past months, with representatives from here travelling over to Honduras to meet with him and broker the deal - and all that hard work has paid off now."
Thomas joins Ben Watson, Michael Brown, Lee cattermole and first-signing Jordi Gomez in the battle for a central midfield spot in what could be a thre-man midfield with a Valencia replacement and Charles N'Zogbia on the wings.