The founders of "Athletes for Hope" also include Warrick Dunn (NFL), Jeff Gordon (NASCAR), Mia Hamm (soccer), Tony Hawk (skate boarding), Andrea Jaeger (tennis), Jackie Joyner-Kersee (track), Mario Lemieux (NHL), Alonzo Mourning (NBA) and Cal Ripken, Jr. (baseball).
"We're all happy with what we've been able to do," said seven-times Tour de France winner Armstrong, a cancer survivor who has raised millions for cancer research.
"The idea is to hand it down to the next group of guys, so they can be active citizens. It's an industry that's very powerful. Sports can affect change."
The dozen founder athletes have already raised a total of half a billion dollars for their respective foundations and charities. The aim of the "Athletes for Hope," is to help other athletes connect to existing charities or get help in starting initiatives of their own.
Agassi, whose foundation was created in 1994 to assist at-risk youth in Las Vegas, said "Athletes for Hope", or AFH, intended to "pass on the passion" for doing charitable work.
"This for us is about sending a clear message to the children, to show the world that it is OK to care," the eight-times grand slam tennis champion said.
"One thing we do have in common is one regret -- that we didn't start our charities early enough.
"We want to reach all those other athletes that have the desire to give.
"Kids aspire to success, to trophies. All of that is a tool, a vehicle to make a difference in other peoples' lives."
The umbrella charity hopes to raise money for initiatives through the sale of an AFH Tag that can be purchased at www.athletesforhope.org. Fans can also use the Web site to find out about volunteer opportunities.