WASHINGTON (AP) — Treasury Secretary Timothy Geithner says regulators waited four years to penalize Barclays bank for trying to manipulate a key global because the investigation was complex.

Geithner told the Senate Banking Committee Thursday that he alerted U.S. and British regulators in 2008 when he learned of problems with the London interbank offered rate, or LIBOR. He was then president of the Federal Reserve Bank of New York