While neither Viacom nor CBS alone is a major Internet player, a merger could create such a powerhouse.

“For us, the Internet is not an add-on — it’s a major, giant new growth business,” Viacom CEO Sumner Redstone said Tuesday during a press conference. “That strategy is enhanced when you marry our Internet strategy into their Internet strategy.”

Neither Karmazin nor Redstone would offer any details about how they plan to integrate the firms’ Internet assets, but each company has said in the past that it would spin off its ‘Net holdings into a separate publicly held company.

Eye for the ‘Net

CBS is the stronger of the two, with CBS.com, MarketWatch.com and Sportsline.com already strong household names in its portfolio.

Over the past several months, CBS has been taking minority stakes in a slew of Web sites such as e-tailer Big Entertainment, Jobs.com, medical site Rx.com, Switchboard.com and automotive-based Wrenchhead.com, using its advertising and promotional outlets as currency.

CBS, for example, acquired a 38% stake in Jobs.com last month for $62 million worth of advertising across its holdings over the next five years.

Viacom’s viable brands

For its part, Viacom has been concentrating on building its non-Internet MTV, VH1, Nickelodeon and Blockbuster brands. Online, MTV, Nickelodeon and Paramount Pictures have noticeable presences. Last month, MTV Networks formed MTV Interactive, an Internet music division to oversee its MTV.com, VH1.com, and SonicNet sites, along with technology from Imagine Radio, as part of its delayed Buggles project.

The new entity is also expected to become a major player in delivering digital music downloads. The company also owns a stake in RioPort, a software maker for such downloads.

In addition, Viacom is readying a hub for children called Project Nozzle that incorporates its Nickelodeon, SimonSaysKids.com and Noggin Web sites.