SAN FRANCISCO — Wilson Sonsini Goodrich & Rosati has appointed litigator Douglas Clark and corporate partner John (Jack) Sheridan as the firm’s co-managing counsel, replacing Steven Bochner, who is returning full time to his corporate practice.

Bochner was named CEO in August 2009, when John Roos left the firm to become the U.S. ambassador to Japan. Bochner said he’s pleased with the firm’s financial performance over the past 2 1/2 years, and that 2011 was the best year in the firm’s history.

But the time was right to start practicing law again, Bochner said, and the firm is fortunate that Clark and Sheridan are ready to take over. The transition will take place over the next month.

“The longer you spend doing things other than practicing, the harder it is to go back,” Bochner said. “I feel very good about the last 2 1/2 years. The firm’s in great shape, and we have a great succession plan in place. We’re not going to miss a beat.”

The announcement doesn’t signal any fundamental changes in the way the firm does business, Sheridan and Clark said. They’ll work as a team, rather than focusing solely on their respective practice areas. And they’re already comfortable working as a team, having worked closely on various committees over the past five or six years.

“We hope this announcement is a reflection of how well Jack and I work together,” Clark said.

An attorney at Wilson since 1993, Clark chaired the firm’s litigation department for six years and is a member of the firm’s policy committee. His litigation practice focuses primarily on defending securities class actions, and he’s represented numerous companies under investigation by the Securities and Exchange Commission. Some of his clients have included Hewlett-Packard Co. and Silicon Valley Bank.

Sheridan joined the firm in 1986 and has been head of the business department for five years, a post he’ll keep for now. Like Clark, he’s also chaired several firm committees. His practice focuses on corporate governance, intellectual property and other corporate legal needs. He represents public and private companies in the technology, life sciences and retail sectors, helping with public offerings, mergers and acquisitions, venture financings and other transactions. He represented YouTube, for example, from its initial financing through its $1.7 billion acquisition by Google Inc.

“Both Doug and Jack have superb strategic and operational expertise that makes them uniquely qualified to pick up the mantle from Steve,” Chairman Larry Sonsini said in a statement. “They know the firm, its people and operations, and the legal business inside out.”