On Tuesday, Citigroup announced a change in leadership for its legal department, appointing Rohan Weerasinghe as the bank’s new general counsel and corporate secretary. Weerasinghe is replacing current GC Michael Helfer, who has been promoted to vice chairman of Citi. Both Weerasinghe and Helfer will report for their new duties on June 1.

Weerasinghe is moving to Citi following a 35-year career at Shearman & Sterling, where he is currently a senior partner, representing financial institutions and corporations on issues including corporate governance, complex transactions, and IPOs and debt issues. In his new role, he will oversee a global network of business unit general counsel, regional general counsel, and corporate deputy general counsel.

Citi CEO Vikram Pandit said in a statement, “Rohan has a great track record as an attorney, and I have tremendous confidence in his abilities. He has a strong international background, leading his firm’s relationships with multinational corporations and financial institutions around the world.”

Helfer, who has been Citi’s GC for nine years, will continue to provide counsel as vice chairman, especially on domestic and international regulatory issues. During his time heading the financial institution’s law department, Helfer oversaw the creation of a significant pro bono program for Citi’s in-house lawyers, which launched in 2005 to contribute to Hurricane Katrina relief efforts.

In a 2007 profile of Weerasinghe by CorpCounsel’s sibling publication the New York Law Journal, reporter Anthony Lin quoted one of Shearman’s clients describing Weerasinghe as a star even in his early days at the firm: “He was one of the few associates clients would look to as if he were a partner.”

Describing his management style, Lin wrote, “Mr. Weerasinghe also has a reputation at the firm as a demanding boss, working his capital markets associates extremely hard. Another former partner said this trait burnished Mr. Weerasinghe’s image as someone who did not merely coast on the firm’s existing relationships but strengthened them and leveraged them in pursuit of new business.”

In the statement from Citi, Weerasinghe characterized the move from Shearman to Citi as an “opportunity to go from one leading global organization to another.”

In fact, it’s the latest link in a long chain of connections between Citi and Weerasinghe’s firm over the years. Shearman first represented Citi’s predecessor, The National Bank of New York, in the late 1800s, and the firm was instrumental in helping the bank grow into one of the largest in the U.S. Shearman continued to represent the financial institution in major business deals throughout the ensuing decades, including a 1998 merger with Travelers Group that led to the establishment of the current entity, Citigroup.