The benefit, airing Jan. 15 at 8 p.m., will also be telecast across all NBC-owned cable outlets: USA, Bravo, Trio, SCI FI, MSNBC and CNBC.
Sources say that "a lot of big names" are interested in appearing on the benefit and that it's just a matter of figuring out logistics.
Radio giant Clear Channel will be a "promotional partner" for the benefit, promoting the telecast on its radio stations across the country.
Meanwhile, in New York City, Ch. 4's tsunami benefit, which airs live Wednesday night at 7 p.m. EST, has added Susan Sarandon and Julianne Moore as guests, where they'll join Sarah Jessica Parker and co-anchors Sue Simmons and Chuck Scarborough.
Dustin Hoffman and Alyssa Milano have been added to the L.A. portion of the guest list, which also includes Clay Aiken, Tea Leoni and "Will & Grace" star Debra Messing.
The Ch. 4 benefit, held in conjunction with UNICEF, will air across all 14 NBC-owned stations nationwide.