Former Top S.E.C. Enforcer Returns To Milbank

After spending the last four plus years investigating financial institutions, George Canellos will now be defending them.

Mr. Canellos, the former co-chief of enforcement at the Securities and Exchange Commission, announced on Wednesday that he would be joining Milbank, Tweed, Hadley & McCloy as a partner and global head of the firm’s litigation department. He will start in mid-March, two months after leaving the S.E.C.

Milbank is familiar turf for Mr. Canellos, who was a partner at the firm before joining the S.E.C. in 2009. And although he spoke to a handful of other large law firms since leaving the government â€" one firm offered him the chance to lead its New York office â€" Mr. Canellos said that he went with his “professional family” at Milbank.

“At the end of the day, it wasn’t a hard decision,” Mr. Canellos said in an interview. “There’s the nucleus of an outstanding practice already there.”

As head of global litigation, Mr. Canellos will run a group that has gradually become Milbank’s largest department. The group covers a wide array of matters, from the sort of securities and white collar cases Mr. Canellos specializes in to other practices like data privacy and mutual fund litigation.

“We’re not the white shoe firm that people think we are,” said Scott A. Edelman, Milbank’s chairman. “It’s a young dynamic firm. We have lots of opportunities to grow,” signaling that Mr. Canellos’s arrival could foreshadow other changes.

Mr. Canellos is the latest Wall Street regulator to switch sides. David Meister, Mr. Canellos’s counterpart at the Commodity Futures Trading Commission, announced last month that he was becoming the head of the white-collar group in the New York office of Skadden, Arps, Slate, Meagher & Flom. And Robert Khuzami, Mr. Canellos’s mentor and predecessor at the S.E.C., recently joined Kirkland & Ellis. Andrew Ceresney, who jointly led the S.E.C.’s enforcement unit with Mr. Canellos and now runs it on his own, joined the agency from Debevoise & Plimpton.

The job hopping raises questions about the revolving door between Wall Street and Washington, as critics complain that it blurs the line between defense and prosecution.

For Mr. Canellos, the revolving door comes with some strings attached. He cannot contact the S.E.C. about official business for one year â€" and is forever banned from defending cases he had a role in investigating.

He also disputed the notion that government lawyers might go soft on Wall Street to bolster their job prospects down the line.

“If you’re in the S.E.C. pulling any punches, no one in the private sector has any respect for you,” he said.

At the S.E.C., Mr. Canellos established a productive yet complicated legacy. He presided over the agency’s crackdown on insider trading, producing cases against some of the biggest-name hedge funds on Wall Street, including SAC Capital Advisors and the Galleon Group. Mr. Canellos also helped reverse a policy at the agency that allowed defendants to “neither admit nor deny wrongdoing,” a decision that was cheered by Wall Street’s critics.

But he also, under Mr. Khuzami, helped drive the S.E.C.’s response to the financial crisis, which has drawn some scrutiny, both internally and from consumer groups. While the S.E.C. filed a number of big cases against banks tied to the crisis â€" including actions against Goldman Sachs and JPMorgan Chase â€" the agency also closed some investigations into Lehman Brothers executives and Wall Street’s role in churning out faulty mortgage securities.

Mr. Canellos, a graduate of Columbia Law School, argued that those decisions came down to the law.

And Mr. Edelman said that Mr. Canellos’s track record at the S.E.C. is highly regarded in the legal world. “People think he did a great job â€" in both the cases he brought and the cases he didn’t bring,” Mr. Edelman said. “He’s a lawyer’s lawyer.”

Mr. Canellos and Mr. Edelman have followed somewhat parallel paths on the way to Milbank. They met more than two decades ago, as young associates at the white shoe firm Wachtell, Lipton, Rosen & Katz. They both then landed at the United States Attorney’s office in Manhattan under Mary Jo White, who is now chairwoman of the S.E.C.

While they both joined Milbank, Mr. Canellos returned to the government in 2009, becoming director of the S.E.C.’s New York office. He moved to Washington in 2012 to become deputy director of enforcement and ultimately the co-chief.

“We’re ecstatic to have George return,” Mr. Edelman said.