Cable television operator Cablevision Systems reported earnings rose to $104.2 million, or 36 cents per share in its first quarter, up from $74.2 million, or 24 cents per share, a year ago. Revenue rose 9.7%, to $1.92 billion, helped by increased subscriptions in its telecommunications unit. The company benefited from significant advertising growth at its Rainbow cable channels, including AMC and We TV. First-quarter profit rose 40%, bolstered by the Bresnan cable systems it acquired last December.