Source: George Mason joining A-10

WASHINGTON -- First VCU, now George Mason. The two mid-majors that made stunning runs to the Final Four from the Colonial Athletic Association will reunite in the Atlantic 10.

George Mason is joining the A-10 as of July 1, an official with knowledge of the agreement told ESPN.com's Dana O'Neil on Sunday night. The conference plans to announce the move Monday, the source said.

The Associated Press also reported George Mason's plans to switch conferences Sunday.

It's the latest domino to fall in a series of interconnected moves that have altered the shape of conferences, both major and mid-major, across the country. The A-10 is losing four schools this year, so it is plucking from the CAA a program that gained prominence with its Final Four run in 2006.

George Mason was one of the founding members of the CAA -- even back when it was previously known as the ECAC South in the 1980s -- but the conference has fallen on difficult times in the past year. Virginia Commonwealth, a Final Four team from the CAA in 2011, just played its first season in the A-10, and both Old Dominion (Conference USA) and Georgia State (Sun Belt) are departing in July.

The men's conference basketball tournament this month had only seven teams because the outgoing schools were banned, while two others -- Towson and North Carolina-Wilmington -- were academically ineligible. No longer with a strong Virginia base of schools, the CAA is taking the tournament to Baltimore next year.

The CAA is welcoming College of Charleston as a new member next season -- giving the conference nine members for 2013-14. Albany and Stony Brook will be new members of CAA Football, an enterprise that operates separately from the conference's other sports.

The A-10, meanwhile, is losing Butler and Xavier to a reconstituted, basketball-focused Big East, while Temple is leaving to join the Big East's football members in a yet-to-be-named conference. Charlotte is heading to Conference USA, also because of football.

The current makeup of the A-10 has been faring well in recent days. VCU, Saint Louis, Butler, La Salle and Temple made the conference a perfect 6-0 in the NCAA men's tournament through Friday's games, although only La Salle survived the weekend to make it to the Sweet 16.

George Mason's move gives the A-10 two schools in the Washington, D.C., market, creating a local conference rivalry with George Washington.

The Patriots men's team is 19-14 this season and will host Houston on Monday in the quarterfinals of the College Basketball Invitational. The women's team is looking for a new coach after Jeri Porter resigned following a 9-21 season.

Information from ESPN.com college basketball reporter Dana O'Neil and The Associated Press was used in this report.