WASHINGTON (Reuters) - The Senate confirmed Harvard economist Jeremy Stein to the Federal Reserve Board, the first vote on one of two nominees to the central bank expected on Thursday.

The vote was 70 to 24 in favor.

If both of President Barack Obama's nominees are approved, it will bring the central bank board up to its full seven-member strength for the first time since 2006.

The Senate has begun voting on the second nominee, investment banker Jerome Powell. The pair could help strengthen the hand of Fed Chairman Ben Bernanke as the board expands its regulatory powers over the country's largest banks as provided by the 2010 Dodd-Frank financial oversight law.

(Reporting By Donna Smith; Editing by Andrea Ricci)