Comcast CEO: 'Bullish and Optimistic' About NBCU

Comcast CEO Goes All in For NBCUniversal

Brian Roberts, Chairman & CEO of Comcast, discusses why he is "bullish" on recent business transactions, including buying GE's remaining 49% stake in NBCUniversal for $16.7 billion. "We've seen some early signs of turnaround and payoff for some of the investments we're making," he added. Both Comcast and GE stock were up on the announcement.

Comcast Chairman and CEO Brian Roberts told CNBC on Wednesday that he's "bullish and optimistic" about the prospects for NBCUniversal.

Comcast announced Tuesday that it will buy the 49 percent of NBCUniversal it doesn't already own from General Electric in a deal worth $16.7 billion.

"We didn't have to do this now and we chose to do it," Roberts said in a "Squawk Box" interview. "If actions can speak louder than words, the action is we're bullish on the businesses we're buying."

Comcast has owned 51 percent of those businesses, which includes CNBC, since January 2011.

"We've seen some early signs of turnaround and payoff for some of the investments we're making," Roberts said, "whether it's in theme parks or in the cable networks or in the broadcast business or in the film business."

He added, "We are bullish and optimistic. And we felt we would have paid more later in all likelihood."

Comcast also released its earnings a day early on Tuesday. Fourth-quarter profits excluding one-time items were $0.52 a share, a penny shy of estimates. Revenue was also a tad short of expectations, coming in at $15.94 billion.

Cable Communications

Roberts said cable "had an outstanding quarter."

Revenue for cable communications increased 7 percent to $10.1 billion in the fourth quarter — fueled by growth in high-speed Internet, business services and video.

"Broadband has been the engine of growth," he said, citing a net gain of 341,000 new customers. "Better than 2011's fourth quarter," he said.

"We only lost 7,000 customers. We're not sure we're there yet for the complete going positive," he said, saying much depends on housing growth.

Putting that in perspective, Roberts said, "[It's] the ninth quarter in a row of improvements in our video losses and to the point that this quarter we would have actually stemmed the tide" if it weren't for super storm Sandy.

He added that Comcast's products and services have gotten better. "Every quarter we're chipping away at it. And there's a real positive direction."

Broadcast Television

Revenue from broadcast television increased 7.9 percent to $2 billion in the fourth quarter — driven by strong primetime ratings at the NBC broadcast network.

"We were surprised to the positive and delighted with the fall ... [but] we should be realistic that this is a multiyear initiative," Roberts said.

With NBC's biggest shows — "Sunday Night Football" and "The Voice" — ending for their seasons, he said, "we're not going to be having the same results that we had in the fall."

—By CNBC's Matthew J. Belvedere; Follow him on Twitter @Matt_SquawkCNBC