Frank Rienzo, left, with former Georgetown basketball coach John Thompson Jr. at Georgetown University construction ceremony. (Rafael Suanes/Georgetown Athletics Communications)

Frank Rienzo, who engineered a major turnaround in Georgetown University’s sports programs as the college’s longtime athletic director and who also was instrumental in founding the Big East Conference, died Nov. 3 at a hospital in Washington. He was 85.

He had complications from congestive heart failure, said a son, Matt Rienzo.

Mr. Rienzo spent 30 years on the Georgetown campus, first as the track coach and later as athletic director, leading a department that included the men’s basketball program, which won the national championship under coach John Thompson Jr. in 1984.

A month after Mr. Rienzo was named acting athletic director in February 1972, Georgetown hired Thompson, a 6-foot-10 Washington native and former NBA player who built the Hoyas’ basketball program into a national powerhouse.

“We don’t expect John Thompson to work a miracle,” Mr. Rienzo said in 1972, “but we’ll be happy if he does.”

In the early 1970s, Georgetown’s annual athletic budget totaled about $400,000. By the early 1980s, Thompson’s Hoyas were creating a financial bonanza for the university. Demand for tickets was so strong that Mr. Rienzo moved most of the team’s home games from the 4,000-seat McDonough Arena on campus to the Capital Centre in Landover, Md. A 1982 matchup with the University of Virginia — featuring Georgetown’s 7-foot center Patrick Ewing and U-Va.’s 7-foot-4 Ralph Sampson — netted the university more than $600,000 for a single game.

Frank Rienzo,right, with coach John Thompson Jr, left, and players Craig Shelton and John Duren, who is hoisting the trophy, after Georgetown won the Big East Tournament in 1980. (Georgetown Athletics Communications/Georgetown Athletics Communications)

“I felt this event was a significant sporting event in the magnitude of a heavyweight championship fight or a Super Bowl,” Mr. Rienzo said at the time. “I don’t want to be money-hungry, but I’m not oblivious to the money potential.”

The university made even greater sums from its frequent appearances in the NCAA basketball tournament and from licensing agreements, which Mr. Rienzo introduced in the mid-1980s. Caps, sweatshirts and T-shirts featuring Georgetown’s logo or its trademarked bulldog mascot were sold by the thousands, earning the university royalties with every sale.

With Georgetown’s growing success on the basketball court, the school dropped most local colleges from its schedule, triggering resentment from athletic directors, coaches and fans at the University of Maryland, George Washington University and American University.

“John Thompson has said for many years that we are trying to win a national championship,” Mr. Rienzo said in 1984, defending his coach, “not the championship of the District of Columbia.”

Instead, Mr. Rienzo helped guide the athletic department on a more lucrative path, largely through new rivalries with teams in the Big East Conference, which he helped form in 1979. Georgetown’s sports teams had previously been independent, but Mr. Rienzo and administrators of six other northeastern colleges banded together to create a new conference with an emphasis on basketball. Mr. Rienzo chaired the Big East’s executive committee for nine of the conference’s first 13 years.

The Big East, which also included Boston College, the University of Connecticut, Providence, Seton Hall, St. John’s and Syracuse as original members, was immediately recognized as one of the country’s premier basketball conferences. Its games were featured on national television, and the Big East became known for a tough, intimidating and intense style of play. Georgetown won the conference’s inaugural championship in 1980.

“If we were going to form into a conference, we should create a conference of schools that have some similarities,” Mr. Rienzo told The Washington Post in 2005. “A historical position about basketball. A commonality of background, of institutional commitment. We wanted to form a conference with good basketball schools and good people.”

In the 1970s, Mr. Rienzo led efforts to raise the profile of women’s sports at the university and also spearheaded the building of Yates Field House, a campus athletic facility for students and intramural sports.

During his tenure, Georgetown’s track-and-field, women’s basketball and golf teams became nationally recognized, and he recruited top coaches in rowing, lacrosse and other sports. By the time he retired in 1999, the number of varsity teams on campus had grown from 11 to 26. From 1988 to 1994, Georgetown received the Big East Conference’s Commissioner’s Trophy five times for fielding the most successful teams across all men’s sports.

Francis Xavier Rienzo was born July 29, 1933, in New York City, one of seven children. His father was a postal worker and janitor.

Mr. Rienzo attended a Jesuit high school in New York and graduated in 1955 from the now-defunct Maryknoll College in Glen Ellyn, Ill. He then became a coach and a teacher of English, Latin and religion. From 1957 to 1969, he coached the track team at Archbishop Molloy High School in New York, building it into a national powerhouse.

At Georgetown, he revived a weak track program and continued coaching for two years after becoming athletic director. During his final years on campus, he helped lead university-wide fundraising efforts.

Mr. Rienzo served on the university’s board of regents for six years and in 2006 was named to the hall of fame of the National Association of Collegiate Directors of Athletics. In 2000, he was inducted into Georgetown’s athletic hall of fame. He and his son Matt Rienzo, an all-American lacrosse player at Georgetown, are the only father and son in the school’s athletic hall of fame.

Mr. Riniezo’s wife of 35 years, the former Joan Rosendahl, died in 1997. Survivors include four children, Francis J. Rienzo of and Matt Rienzo, both of Kensington, Md., Teresa Paquette of Vienna, Va., and Cecilia Castiello of Bethesda; two sisters, Mary Elizabeth Noll of Morristown, N.J., and Bernadette Rienzo of Washington; two brothers, Ignatius Rienzo of Hauppauge, N.Y., and Gregory Rienzo of Oakland, Calif.; and 16 grandchildren.

“There seems to be some confusion in the university as to what the goals of the athletic department should be,” Mr. Rienzo said when he became athletic director in 1972. “Personally, I believe athletics play just as important a role in education as any other area. To me, it’s analogous to a course in literature. If you want to avail yourself of that educational advantage, you do it.”

An earlier version of this story stated that women were not admitted as undergraduates to Georgetown until 1969. Women had attended some schools at the unviersity before then, but they were first allowed to enroll in the undergraduate College of Arts and Sciences in 1969.