Spain international forward Inaki Williams has signed a four-year contract extension with Athletic Bilbao until 2025, the club said on Wednesday.

The 23-year-old winger's release clause has been increased from 50 million euros ($61 million) to 80 million euros although it will progressively increase to 108 million euros.

Williams, who was born in Bilbao to Liberian parents, has scored six goals in 26 matches this season.