President Barack Obama has chosen Elisse Walter, one of five members of the Securities and Exchange Commission, to lead the agency after Chairman Mary Schapiro leaves next month.
She will take over at a critical time for the agency, which is finalizing new rules crafted in response to the 2008 financial crisis.
Walter, a Democrat, can serve through the end of next year without Senate approval because she's already been confirmed to the commission. She was appointed to the SEC in 2008 by President George W. Bush.
Before that, Walter served under Shapiro as a senior official at the Financial Industry Regulatory Authority, the securities industry's self-policing organization.
Obama said in a statement: "I'm confident that Elisse's years of experience will serve her well in her new position, and I'm grateful she has agreed to help lead the agency."
Obama previously designated Walter as acting SEC chairman in January 2009 before Schapiro was confirmed and took office.