Daniel Cunningham, a partner at Quinn Emanuel Urquhart & Sullivan who was recognized as a leading practitioner in the area of structured finance, died on March 31 of complications related to cancer, his firm said. He was 69 years old.

Before joining Quinn Emanuel in 2009, Cunningham spent 23 years at Cravath, Swaine & Moore, where he was at one time the managing partner of the London office, before joining Allen & Overy in 2001 as senior partner and co-head of the U.K. firm's global U.S. practice.

Quinn Emanuel managing partner and founder John Quinn, who knew Cunningham since their time together at Harvard Law School, said he was “a great partner and a friend.”

A leading authority on transactional law who was “widely recognized as a principal architect of the ISDA Master Agreements and related ISDA credit derivatives,” Cunningham was one of the “most knowledgeable lawyers in the world regarding derivatives and other types of structured finance instruments,” according to his Quinn Emanuel biography. 

Cunningham used this knowledge to become a key member of Quinn Emanuel's litigation strategy when he joined in 2009. “Just as the financial crisis hit in 2008, Dan called me up and said, 'it isn't going to be fun to be a corporate lawyer for a while,'” said Quinn. After almost 30 years in corporate and financial law, Cunningham became a litigator.

“We have dozens of cases arising out of the subprime mortgage securitizations,” Quinn said in the announcement of Cunningham's hiring in 2009. “Dan is going to be working with our structured finance litigation team in understanding the documentation and identifying claims.”

Quinn said Cunningham was integral to Quinn Emanuel's substantial success in litigating opposite big U.S. and global banks in the wake of the financial crisis. The firm secured more than $20 billion in settlements in litigation on behalf of the Federal Housing Finance Agency alone. 

“He helped us understand where the banks' vulnerabilities were in different structures and financial products,” Quinn said. “He understood these things as well as or better than the bankers and institutions that created them.”

He also praised Cunningham's personal side. “He loved good food, good wine, good cigars,” Quinn said. “[You] never met a more positive, upbeat person than Dan. You always felt better being around him.”

Cunningham was active outside of his law practice as well. He was on the executive committee of the PRIME Finance Foundation and a board member of Job Path, an organization that “supports people with developmental disabilities as they make choices about their lives and play valued roles in their communities.”

“He led us with wisdom, intelligence, and clear-eyed commitment to our mission,” the trustees of Job Path said in a statement.  “We will endeavor to continue our work as Dan lived his life, with grace and generosity of spirit.”

Cunningham is survived by his wife and two children.