Charter Communications, the cable company controlled by billionaire Paul Allen, said Tuesday that it narrowed its second-quarter loss amid revenue gains in high-speed data subscriptions.

The St. Louis-based company reported a second-quarter loss of $356 million versus a loss of $415 million a year ago. Revenue advanced 7 percent to $1.3 billion.

The improvement came as Charter saw its high-speed-data revenue surge 25 percent, thanks in large part to nearly 311,000 net new high-speed data customers in the quarter. The company’s video revenue rose 2 percent.

The video subscriber numbers proved to be a mixed bag for Charter. The company said it lost 41,700 basic-cable subs, far fewer than many analysts had expected. However, analysts’ predictions that the company would gain digital cable subscribers proved off the mark, since Charter lost 9,000 digital customers.