NBC exec, parish school advocate.

Mr. Donnelly, who had previously served as the chief financial officer of Comcast Corp.’s programming division, was instrumental in that company’s growth into a cable powerhouse and also played a key role in the company’s successful merger with NBCUniversal in 2011, said Brian Roberts, the chairman of Comcast Corp.

“Joe was such a wonderful, warm person and a strong, quiet leader,” Roberts said. “He was an important part of our company’s growth – and of our company’s culture. We will miss him so much.”

Mr. Donnelly was also respected for his compassion and dedication in helping Philadelphia’s Catholic schools.

For the last five years, Mr. Donnelly, a graduate of Monsignor Bonner High School, had served as a board member of the Business Leaders Organized for Catholic Schools (BLOCS), a nonprofit group dedicated to raising scholarship and endowment money for the financially struggling schools of the Archdiocese of Philadelphia. “He was a great board member and a caring and generous individual who poured his time, heart and soul into it,” said Michael O’Neill, the chairman of BLOCS.

As part of his involvement with BLOCS, Mr. Donnelly recently helped rescue the Saint Cyril of Alexandria parish school from closure.

For more than a year and a half, Mr. Donnelly volunteered his time and business acumen to help school officials sort through their financial records for a better understanding of their financial situation, said Bill O’Brien, the development director for BLOCS.

After the school was slated for closure earlier this year, Mr. Donnelly worked to help the school file an appeal with the archdiocese.

“For the last three or four months he worked his tail off to help them make the case to stay open,” O’Brien said.

Mr. Donnelly met his wife, Patty, as an accounting student at St. Joseph’s University. The couple married in 1987, 10 days after Mr. Donnelly graduated from the Wharton School of the University of Pennsylvania.

“He had it all planned out,” Patty Donnelly said.

The couple had four children – Kevin, Patrick, Christine, and Melissa – and would have celebrated their 25th anniversary this spring.

In 1996, Mr. Donnelly went to work for Comcast’s corporate development department and, according to a 2007 profile in Broadcasting & Cable magazine, was key in orchestrating a string of acquisitions and mergers – including Comcast’s $47 billion merger with AT&T Broadband in 2003.