Comcast Corp posted stronger quarterly earnings on Tuesday as its benefited from healthy ad sales at its newly consolidated NBC Universal joint venture and added more Internet and phone subscribers.

The No. 1 U.S. cable operator said net income rose to $943 million, or 34 cents a share, up from $866 million, or 31 cents a share. Excluding costs related to the NBC Universal transaction profit came in at 36 cents.

Comcast added more than 418,000 high speed Internet subscribers during the quarter and 260,000 phone subscribers.

Analysts at Collins Stewart had estimated that Comcast would add 300,000 Internet subscribers and 207,000 phone subscribers.

Comcast lost just 39,000 video subscribers, the lowest number of video subscribers in four years since it started facing stiff competition for video customers from phone companies' digital video services including Verizon Communications' FiOS and AT&T Inc's U-verse.

Collins Stewart had forecast Comcast would lose 95,000 video subscribers.

The cable numbers were strong and the financials were in line or better than expected, said Craig Moffett analyst at Bernstein Research. For all the attention around NBC Universal, it's still a cable story.

Philadelphia-based Comcast, which has about 23 million subscribers, struck a deal with General Electric Co in December 2009 to take a 51 percent in a newly created $30 billion NBC Universal joint venture. The deal closed on Jan 28 this year.

Comcast's first quarter pro forma revenue rose by 6.1 percent to $13.3 billion including a full quarter of NBC Universal earnings but excluding the impact of last year's Winter Olympics.

Comcast's reported revenue was $12.13 billion for the first quarter as the cable company took control of NBCU on January 28.

NBC Universal pro forma revenue was up 5 percent to $4.35 billion, excluding the impact of last year's Winter Olympics.

Advertising revenue for the first three months of the year grew 14 percent at NBCU's cable networks to $769 million while NBC Entertainment saw its advertising revenue rise by 8 percent to $910 million.

Comcast shares, which closed at $26.61, rose slightly by 1 percent in after-market trading.

(Reporting by Yinka Adegoke; Editing by Phil Berlowitz, Bernard Orr)

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