Cablevision (CVC) almost halved its profit during the first quarter despite improving subscriber metrics across its three mains business lines due to the loss of income from its spun-off AMC Networks. 

Average monthly revenue per basic video customer climbed 1.9% to $152.52, however earnings were held down by the loss of AMC (AMCX), which hosts popular shows such as "Mad Men" and contributed $35 million to net income last year. 

By spinning off AMC last summer, Cablevision was betting the division would perform better on Wall Street on its own, boosted by the success of its lineup of shows, which also includes "Breaking Bad," and channels.

While AMC's shares have climbed 23.5% over the last 10 months, shares of Cablevision have plummeted 58.5%. They were down another 3% to $14.25 shortly after reporting quarterly results on Thursday.

The Bethpage, N.Y.-based cable provider added 7,000 new video subscribers but only earned $57.2 million, or 21 cents a share, down sharply from $104 million, or 37 cents, a year ago.

Analysts in a Thomson Reuters poll were looking for a profit of 19 cents.  

Revenue for the three months ended March 31 was up slightly year-over-year to $1.66 billion, but narrowly missed the Street’s view of $1.67 billion. 

The company added a total of 41,800 and 42,400 high-speed data and voice customers, respectively.

In a statement, Cablevision CEO James Dolan said customers are responding to ongoing efforts to expand and improve its products, such as the recent introduction of its Optimum app for laptops and continued investments in WiFi.

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