President Barack Obama has re-nominated a Nobel Prize-winning economist to the Federal Reserve despite opposition from Senate Republicans.

The president's initial nomination of Peter Diamond fizzled when the Senate adjourned in late December without acting on it. Obama on Wednesday resubmitted nomination to the newly convened Senate, where Republicans now hold six additional seats. That likely will make Diamond's confirmation even more difficult.

A professor at the Massachusetts Institute of Technology, Diamond is an authority on Social Security, pensions and taxation. He shared the Nobel Prize in economics that was awarded in October. Senate Republicans have questioned his practical experience and research.

Diamond was tapped to fill one vacancy on the seven-member Federal Reserve Board. If confirmed, he would take part in decisions affecting employment, economic growth and inflation.