The TV network, who took over the name rights to the team formerly known as the US Postal squad, were spearheaded by Lance Armstrong in the first year of their association in 2005 and won the Tour de France - Armstrong's seventh.
But the company said that they wished to focus on its "core business" in the future.
The team's top rider in 2007 is Italian Ivan Basso, who has moved over from Danish team CSC.
Giro d'Italia
Cummings and Roche ready to roar
11/05/2007 AT 19:02
Armstrong's agent and attorney Bill Stapleton told the paper the decision not to renew for a fourth year was made after the firing on Monday of Discovery Networks president Billy Campbell by new Discovery Communications president and CEO David Zaslav.
"This would not have happened if Billy Campbell was still there," Stapleton was quoted as saying. "This is about their change in management."
Pro Tour 2007
Basso denies taking drugs
08/05/2007 AT 11:52
Pro Tour 2007
Basso had crisis of conscience
07/05/2007 AT 17:39