Spain's Santander , the euro zone's largest bank, said on Monday its Chief Executive Alfredo Saenz, 70, had stepped down after a prolonged legal battle over whether he should be barred from banking due to a criminal conviction.

The Bank of Spain opened new proceedings earlier this month to decide Saenz's future after the government passed a law that could have helped him retain his post.

Santander said it has named Javier Marin, who has been the bank's managing director, as new CEO.

(Reporting By Tracy Rucinski; Editing by Fiona Ortiz)