The Atlantic Coast Conference on Sunday announced a swift and decisive step to broaden its geographic and economic footprint by officially inviting Syracuse University and the University of Pittsburgh to join the league.

The move comes at a time of increasing tumult in the conference alignment of college sports, as major university athletic departments seek to maximize revenue through lucrative television contracts handed out to the most visible conferences and schools.

By adding Pittsburgh and Syracuse, the ACC in one bold stroke extended its television market and recruiting base to virtually the entire Eastern Seaboard, raised its athletic profile and girded against potential raids of its schools by other conferences.

“This is indeed a monumental day in the history of our league,” ACC Commissioner John Swofford said Sunday in a teleconference with reporters.

But at the same time, the ACC’s power play also jeopardized the stability and status of the Big East, the conference that has been home to Syracuse and Pittsburgh, and also includes men’s basketball power Georgetown.

It also deprives Georgetown of the conference rival its fans most love to hate, Syracuse, and the chance to regularly showcase its athletes in the country’s largest basketball arena, Syracuse’s 33,000-seat Carrier Dome.

The Big East now has lost five members that field high-level football teams to the ACC since 2004;Virginia Tech, Miami and Boston College left for the ACC in the ACC’s last expansion. With the departures of Syracuse and Pittsburgh and next year’s expected arrival of Texas Christian, the Big East would be left with only seven schools that play big-time college football, an untenable situation for any conference that wishes to remain in the Bowl Championship Series, the six-conference conglomerate that controls the financially lucrative bowl bids handed out to the league champions. (Georgetown is one of 10 current Big East members that does not play in the top tier of college football.)

Georgetown Athletics Director Lee Reed said in statement: “As a founding member of the Big East in 1979, we have confronted challenging moments in the past and we are confident that as we work through the events of the past days we will maintain the high quality of the Big East Conference.”

It was not immediately clear when the move by Syracuse and Pittsburgh would take effect. The Big East requires schools to give 27 months notice of plans to leave the conference and a payment of $5 million, but the timetable could be accelerated.

Swofford said Sunday that hurting the Big East was not the ACC’s intent. Rather, he said, the ACC had to protect its interests and had received overtures from a “double-digit” number of schools wanting to join the conference.

“In all my years of college athletics administration, I’ve never seen this level of uncertainty and potential fluidity among schools and conferences,” said Swofford, 62. “Schools are looking for stability. . . . And I think the conferences that appear to be stable moving forward are going to receive inquiries.”

But the ACC won’t necessarily stop at 14 schools. Maryland and Duke, charter members of the ACC, are among those advocating for further expansion to 16 to provide compelling divisional rivalries and simplify scheduling in football and men’s basketball, the sports that drive revenue and reputation in major college sports.

“Everybody has talked about the changing climate of college athletics, and we in the ACC wanted to make sure that we were going to be at the forefront and be able to attract the kind of members that fit our conference profile,” Maryland Athletic Director Kevin Anderson said in an interview. “At Maryland, we’re optimistic. We don’t think it’s going to stop there. We would support adding two more members with open arms.”

By adding Syracuse and Pittsburgh, two pillars of the Big East, the ACC restores the basketball hegemony it had ceded in recent years. The Big East sent a record 11 of its 16 teams to the NCAA men’s basketball tournament last season. The ACC managed just four NCAA tournament berths, with Maryland among the eight missing out.

Schools are also looking for money. The economic downturn has slashed public funding for higher education, college sports included. And as spending on college sports increases, athletic departments are seeking new ways to pay the bills. Among them: belonging to a major conference and sharing in the spoils of its lucrative TV deal. (The ACC’s deal with ESPN is projected to yield $13 million annually to each of its 12 member schools.)

Swofford expressed confidence that each school’s share would rise, rather than be diluted, once terms of the ESPN deal are renegotiated to reflect the addition of Syracuse and Pittsburgh.

While swift in execution, the foundation for the ACC’s latest expansion was laid 18 months ago in an effort to avoid the political rancor, legal conflict and internal disagreement that dogged the league’s addition of Miami and Virginia Tech in 2004 and Boston College in 2005.

Anticipating another spate of conference-jumping amid the scramble for new revenue, Swofford in early 2010 appointed a 12-member panel to study the question of ACC expansion and evaluate potential candidates.

Until last week, the prevailing sentiment was that the ACC was best served by standing pat at 12 members — Boston College, Clemson, Duke, Florida State, Georgia Tech, Maryland, Miami, North Carolina, North Carolina State, Virginia, Virginia Tech and Wake Forest.

But upheaval in the Big 12 Conference brought a new sense of urgency, with Texas A&M’s plan to bolt for the Southeastern Conference triggering fears of rampant poaching among college sports’ six major leagues. In many respects, the dominoes had started falling in June, when the Pacific-10 Conference added Colorado and Utah and became the Pacific-12.

According to Swofford, the ACC’s so-called 4-4-4 committee (composed of four presidents, four athletic directors and four NCAA faculty representatives) met Tuesday to discuss expansion. ACC presidents met that night. And discussion continued through the week, with the league raising its “exit fee” for any school that wanted to leave the ACC to $20 million and ultimately agreeing that Syracuse and Pittsburgh best fit the ACC’s academic and athletic profile and could best strengthen its negotiating hand with its TV partners.

“I don’t think it’s really a reaction to that,” Swofford said when asked if Texas A&M had been the catalyst, “although in a subtle way, when you look over the past year or so and see the movement with the Pac-12 that could potentially have gone further, the Big Ten expanded, the SEC expanding, that all comes into play — not necessarily in a measurable kind of way. But our interest is always about what’s best for us.”

While Swofford said the ACC was “very comfortable” with 14 members, he quickly added, “We are not philosophically opposed to 16.”

According to a source close to the process, there are two trains of thought regarding a 15th and 16th ACC member.

Some favor the Big East’s Connecticut and Rutgers because they’re in the Eastern time zone and naturally encompassed in the ACC’s blanket coverage of East Coast markets. Others feel that Texas, Notre Dame or other schools with comparable football clout would represent the bigger coup. Florida State, in particular, would like the ACC to raise its football profile by landing two more gridiron powers.

Details regarding division assignments and scheduling for the 14-team ACC are far from complete. But Swofford conceded that it only made sense to include New York’s Madison Square Garden in the rotation for hosting the ACC basketball tournament each March. The Big East’s contract to stage its tournament at the Garden runs through 2016.

Staff writer Tarik El-Bashir contributed to this report.