The Carlyle Group suffered its second passing in as many months, as Richard Darman, a senior adviser to the firm, died earlier today after a battle with leukemia. He was 64 years old.

The news comes a little more than a month after Michael Connelly passed away. Connelly, who had also been a senior adviser to Carlyle, died at the age of 55, also due to cancer.

Darman joined the private equity firm in 1993. In a memo to employees, the firm described him as “instrumental” to the launch of the firm’s global venture and growth capital groups, as well as its partnership with the Riverstone energy investing team.

He joined Carlyle after serving as the director of the U.S. Office of Management and Budget, which was part of the cabinet of the former President, George Bush Sr. Prior to that Darman had put in stints as a managing director at Shearson Lehman Brothers, as the deputy secretary of the U.S. Treasury, and as an assistant to the President of the United States.

Alongside his career, Darman was also active in philanthropy. He was a trustee of the Howard Hughes Medical Institute, the chairman of the Smithsonian National Museum of American History, and a member of the Overseers’ Visiting Committee at Harvard University, where he attended both undergrad and business school, graduating in 1964 and 1967, respectively.

“His towering intellect and voracious appetite for knowledge made him a formidable asset and ally,” the Carlyle memo read.

Darman is survived by his wife Kathleen, and three sons, William, Jonathan and Emmet.

Career moves Energy industry Infrastructure (M&A)