Charter Communications became the second MSO in the space of a week to announce an actual increase in basic video subscribers, joining Cablevision in reporting what has become a rare event in a mature and competitive market.

Charter added 20,000 video subscribers, 141,000 broadband subscribers and 31,000 phone customers in its recently concluded first quarter of 2012.

Cablevision earned its increase in customers through discounted promotional offers, agitating analysts whose reaction sent Cablevision’s stock price down on the news. Charter seems to have avoided that fate; it’s stock was trading up immediately after announcing its financials today.

More than many major U.S. MSOs, Charter has actively embraced broadband delivery of video, including philosophical acceptance of the cord-cutting phenomenon. Cord-cutting continues to be only an incipient trend, but Charter is one of the few service providers that provides the line-item information of “non-video customers.” The percentage of the company’s residential non-video customers has grown from 12.9 percent to 16.9 percent since the first quarter of 2011.

First quarter revenue was $1.82 billion, up a few percentage points from the similar quarter a year ago. Charter said revenue growth was driven by strong customer growth within the first quarter of 2012, offset by net video customer losses in the trailing 12-month period. ARPU was up 7 percent from a year ago, to $146.77. Business revenue was also up.

The company narrowed its net loss, from $110 million in the year-ago first quarter to $94 million in the first quarter just completed. More than the increase in customers or the increase in ARPU, Charter attributed the improvement to “the decrease in net loss, offset by a decrease in weighted average shares outstanding as a result of the repurchase of 14.6 million Charter Class A shares.”

Tom Rutledge, the company’s new president and CEO, said: “We are effectively executing on our strategic priorities of delivering a great customer experience, capitalizing on our market-leading Internet product, improving our video and voice products, and growing our commercial business. We are accelerating certain initiatives, including driving digital penetration through additional HD channel launches, a more simplified packaging and pricing structure, and an enhanced product offering, all of which provide more value to our customers. We will move quickly to capitalize on these opportunities and leverage our powerful network to grow our business.”