July 15 (Reuters) - Silent Circle, a Geneva-based pioneer in the field of securing mobile communications, said on Friday that it has raised $50 million in a Series C financing round led by Santander Bank.

Proceeds from the round, which closed in late May, will be used to fund development of software products targeted at businesses, government agencies and law enforcement, Silent Circle interim Chief Executive Matt Neiderman told Reuters.

Some of the funds have already been used to retire the company's debt, he added.

(Reporting by Jim Finkle)