Beginning Sept. 5, the CBS Evening News with Katie Couric will be simulcast live on the Internet, Sean McManus and Larry Kramer announced today.

The webcast will be free and ad-supported. “The move, announced this morning, makes CBS News the first of the network newscasts to use the Internet for simultaneous transmission of the news,” Broadcasting & Cable says.

Kramer tells mediabistro.com that the network has negotiated a new agreement with CBS affiliates that allows the simulcast to happen.

There’s one catch: “To access the simulcast, viewers will be asked to register so that they view it when the television broadcast is aired in their time zone,” CBS says.

McManus calls the simulcast is “a groundbreaking development in making the program available to the largest possible audience.” He added: “It’s another giant step towards providing CBS News content to people wherever they are — in their homes, in their offices, in their cars, on their computers or on their cell phones.” The program will also be available on-demand…