Guillermo Ulacia

Arnaiz served as the chief executive officer of Gamesa Corporación Tecnológica from December 1, 2005. He has previously served as Vice Chairman of General Motors Corp, Spanish unit; he also served as Executive Chairman since July 2006 until October 2009.^{[citation needed]}

Arnaiz worked for 10 years as a Director of flat steel products at Arcelor before becoming Vice President.^{[citation needed]}

Arnaiz serves as Co-Chairman of the Aceralia Management Committee, member of the General Management of the Arbed Group.^{[citation needed]}