ABC, CBS and NBC will air a simultaneous one-hour fundraiser for cancer research in prime-time on Sept. 5.

The "Stand Up to Cancer" broadcast will feature musical performances and celebrity appeals, although no guests were immediately announced Tuesday. The American Association for Cancer Research will distribute the money raised to specific organizations.

The three network evening news anchors — Katie Couric, Charles Gibson and Brian Williams — were to announce the plans on the network morning news shows Wednesday, but word slipped out earlier.

"For people struggling with this disease, or those who will be diagnosed, scientific breakthroughs can be a matter of life or death — literally," said Couric, whose husband and sister both died of cancer. "We want everyone to know that they can make a difference in this fight."

Hollywood producer Laura Ziskin, a cancer survivor, will produce the event.

The rare simultaneous broadcast is reminiscent of a benefit for survivors of the Sept. 11 terrorist attacks that was aired on many networks weeks after the event.