Insight Communications brought in $261.4 million in revenue in its first quarter, a 10 percent increase year-over-year.

Total customer relationships as of March 31 were 784,900, an increase of 7,900 compared with the first quarter of 2009. And revenue-generating units (RGUs) increased by 110,200, or 6 percent, year-over-year to total 2.08 million at the end of Q1 2010.

In the first quarter, Insight – the ninth-largest U.S. cable operator – added 40,800 net RGUs.

Insight added 6,400 basic subscribers in Q1, while most cable ops are losing them, to total 722,700 basic subs. Digital subs brought on in the first quarter amounted to 18,500, for a March 31 total of 527,900.

High-speed Internet additions in the first quarter were 14,700, leaving Insight with a total of 516,300. And Insight saw a voice customer gain of 1,300, for a total of 315,700 at the end of the quarter.

As of March 31, Insight said that 99 percent of the company’s customers were passed by two-way, 750 MHz or a higher-capacity network.