WASHINGTON (

TheStreet

) --

Federal Reserve

Vice Chairman Donald Kohn, who helped steer the Fed as its number two throughout the economic crisis, will retire at the end of his term in June.

Kohn submitted his resignation letter to President Obama, dated Monday, according to a release from the Fed. The resignation also opens a third spot on the Fed board of governors that Obama will need to address.

In the same release, Fed Chairman Ben Bernanke said the "Federal Reserve and the country owe a tremendous debt of gratitude to Don Kohn for his invaluable contributions over 40 years of public service."

Donald Kohn, vice chairman of the Federal Reserve.

Besides helping navigate the Fed through the financial crisis, Kohn is also known for heading the so-called "stress tests" that examined the strength of several major financial firms.

Calling the job "an honor," Kohn said in his resignation letter that the Fed was tested throughout the crisis. But he was "confident that history will judge the Federal Reserve under the leadership of Chairman Ben Bernanke, to have met these challenges with great speed, imagination, and effectiveness."

Kohn was named vice chairman in June 2006. He has been a Fed board member since August 2002. Before that, he served as adviser to the Board for Monetary Policy and secretary of the Federal Open Market Committee, among other positions.

A Philadelphia native, Kohn received his Ph.D. in economics from the University of Michigan in 1971.

-- Written by Sung Moss in New York