David Brenneman, a Harvard-trained lawyer who crossed into finance and was an executive director in equity risk management at Morgan Stanley, has died. He was 37.

He died on Aug. 31 at Memorial Sloan-Kettering Cancer Center in Manhattan following a 16-month battle with leiomyosarcoma, or LMS, a rare cancer of the soft tissue, according to his wife, Mina Brenneman. A father of three, he was a resident of Chappaqua, New York, and stopped working only in mid-July when he had his final surgery, his wife said.

At Morgan Stanley, owner of the world’s largest brokerage, Brenneman specialized in prime brokerage and worked at the firm’s Manhattan headquarters in Times Square, spokesman Mark Lake said. Prime brokerage typically supplies cash management and securities lending to clients including hedge funds and other large investors.

Brenneman jumped to finance after starting his career in another demanding field, law.

“After the birth of his first son, he couldn’t stand the hours anymore,” Mina Brenneman said today in an interview. “He went from 80 hours a week to 60 hours a week. We thought that was a vast improvement.”

‘Second Family’

In April, about 200 Morgan Stanley colleagues attended the annual fundraising gala of the Sarcoma Foundation of America to see Brenneman receive the group’s Courage Award for “strength and perseverance” in battling the disease. He raised hundreds of thousands of dollars toward sarcoma research.

“Over the past year, I really can say that Morgan Stanley has become part of my treatment process, part of my recovery, a second family to me,” Brenneman told the gathering, according to a home video that his brother, Michael, posted on YouTube. “I couldn’t imagine going through this without such a supportive group of colleagues, such a generous group of colleagues.”

In addition to his award, Brenneman was presented with a framed photo of a crowd of Morgan Stanley employees posing in Times Square in front of a congratulatory message on an electronic news ticker on the headquarters building above. Arranging the group picture briefly stopped traffic, his wife said.

David Cameron Brenneman was born on April 10, 1976, in Natick, Massachusetts, to Ruth and Tom Brenneman, both teachers. He ran track, played soccer and was captain of the basketball team at Natick High School.

‘Two Revolutions’

At Colby College in Waterville, Maine, where he graduated summa cum laude in 1998, Brenneman majored in international relations and Russian. According to Colby’s Web site, he gave a “senior scholar” presentation in 1998 titled “The Evolution of the Literary Myth of St. Petersburg Between Two Revolutions.”

He received a master’s degree in Slavic studies from Yale University, in New Haven, Connecticut, in 2000 and a law degree four years later from Harvard Law School in Cambridge, Massachusetts.

He joined the New York-based law firm of Davis Polk & Wardwell LLP where, in 2006, he advised investment bank Greenhill & Co. on the closing of an $80 million fund with Silicon Alley Venture Partners LLC, according to an article in the Daily Deal. Greenhill was founded in 1996 by Robert Greenhill after he led Morgan Stanley into the mergers and acquisitions advisory business.

Brenneman’s first job in finance was as a vice president at Banc of America Securities, the investment-banking arm of Bank of America Corp., now known as Bank of America Merrill Lynch. He moved to Morgan Stanley in 2008.

With his wife, the former Mina Nedialkova, whom he met at Yale in 1998, Brenneman had three children -- sons William, 8, and Alexander, 6, and daughter Margaret, 3.

In addition to his parents, wife, children and brother, survivors include a second brother, Matt Brenneman.

A fund started by his family to raise money for Brenneman’s treatment is now raising money for his children’s college educations.