Bilbao (Spain), June 30 (IANS): Football club Athletic Club Bilbao announced that they have reached an agreement with Spain international Iker Muniain to extend his contract until the end of June 2019.

The deal means a two-year-extension to the deal tying the 22-year-old to the club where he has spent his entire career and for whom he holds the record of being the youngest player to debut in the first team aged just 16 years, seven months and 11 days, reports Xinhua.

Muniain, whose buy out clause remains set at 45 million euros, is currently recovering from a knee operation after he damaged his cruciate knee ligaments in a game against Sevilla in early April and will not return to first team action until October.

His new contract is part of a concerted effort by the club to assure the future of its most important players. Defender Aymeric Laporte also recently signed a new deal as did Xabi Etxeita and striker Aritz Aduriz.

The news completes a good 24 hours for the Basque club which only plays footballers either born or raised in the Basque region. Sunday saw the club's B-team 'Bilbao Athletic' win promotion to the Liga Adelante (Spanish second division) after achieving a 3-1 aggregate play-off final win over Cadiz.

That means Athletic are the only Spanish club to have its B-team in the second division after Barcelona B were relegated last season and Real Madrid Castilla failed to make the play-offs despite several important signings and having Zinedine Zidane as coach.