Susan Merrill, who is stepping down as the head of enforcement at the Financial Industry Regulatory Authority, Wall Street's self-regulatory body, is set to become a partner at the law firm Bingham McCutchen LLP.

Ms. Merrill, 53 years old, will lead Bingham's enforcement practice and advise clients on regulatory and securities enforcement matters. She will join the firm's New York office this week.

"Susan is a recognized leader in the securities field," Jay Zimmerman, Bingham's chairman, said in a statement. "Her arrival to Bingham exemplifies our investment and commitment to building the strongest securities team."

Ms. Merrill was hired by the New York Stock Exchange in 2004 to help revive its regulation division. She became head of enforcement at Finra in 2007 when the National Association of Securities Dealers merged with the regulatory arm of the NYSE, forming Finra. Previously, Ms. Merrill was a litigation partner at New York law firm Davis Polk & Wardwell LLP.

At Finra, Ms. Merrill helped to merge the enforcement departments of the NASD and NYSE, and brought a number of auction-rate-securities cases against Wall Street firms.