Borja Valero has left West Brom and joined Villarreal on a permanent basis after initially spending last season on loan with the Primera Liga club.
The Spanish midfielder, 26, was a record signing at The Hawthorns when he joined from Real Mallorca for £4.7million in 2008.
But he failed to settle in the Midlands and returned to Mallorca on a season-long loan a year later.
The former Real Madrid youngster, capped once by Spain, then signed for Villarreal on a similar loan deal for the 2010/11 season with the view to making the move permanent in the summer.
His 35 league games and three goals suitably impressed the Villarreal hierarchy and Valero has now completed a deal for an undisclosed fee.