In a 175-page filing with the Federal Communications Commission, the two cable and Internet giants said their combination will "provide unique benefits to both consumers and businesses" and "broadly advance the public interest in multiple concrete ways."
The public interest filing is phase one of Comcast and Time Warner Cable's efforts to get their deal -- valued at more than $40 billion through regulators and lawmakers. On Wednesday, the Senate Judiciary Committee will hold a hearing scrutinizing the transaction, the first of what will likely be several hearings held by various House and Senate committees.
The Justice Department is also conducting an antitrust review of Comcast's proposed acquisition of Time Warner Cable.
Media watchdogs and consumer activists have been loudly protesting a combination of the nation's top two cable operators since the deal was unveiled in February. A combined Comcast-Time Warner Cable would have more than 30 million pay-TV subscribers in many of the nation's biggest cities, including New York and Los Angeles.
Comcast has said it would sell some cable systems to bring its national reach to under 30%, even though there are currently no FCC rules limiting the national reach of a cable operator.
The merged entity would also become one of the nation's largest broadband provider as well, and there is a concern that such a scenario could lead to abuses of power.
"Merging the nation's two biggest cable-Internet providers would turn Comcast into our communications gatekeeper, able to dictate the cost and content of news, information and entertainment," said Craig Aaron, president of media reform group Free Press. "We need an Internet and video marketplace that offers people high quality options at prices they can afford -- not a near-national monopoly determining what we can watch and download."
Comcast and Time Warner Cable are also large content providers. Comcast is the parent of NBCUniversal, parent of Universal Studios, NBC and several powerful cable channels including USA, CNBC and MSNBC. Time Warner Cable owns local sports and news channels including New York 1 and SportsNet in Los Angeles, which carries Lakers games.
In their filing, Comcast and Time Warner Cable argue that the deal shouldn't raise any anticompetitve concerns because the two media giants do not compete head-to-head in any relevant way so there will be no diminished competition for consumers.
As for concerns about the potential national reach, the two companies said that was irrelevant because it will still face the same level of competition as a combined entity.
Comcast executives have said they hope the deal could be approved by the end of the year.
Follow Joe Flint on Twitter @JBFlint.
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