Customers across the Carolinas could be seeing higher rates for cable, Internet and phone service, Time Warner Cable said.

Spokesman Dan Ballister said Wednesday the company started sending out notices about the rate increases last month. About 77 percent of customers won't see any changes to their bills now, Ballister said, because they are currently covered by promotional offers or discounts.

The remaining 23 percent of Carolinas customers will see an average increase of 4 percent in their monthly bill, Ballister said. Increased costs for programming, network upgrades and new features are the main causes of the price increase, he said.

An estimate of what that might equal in dollar amounts wasn't available, Ballister said, due to the wide variation in services and bundles customers currently have.

Among the changes Time Warner Cable said are driving the higher rates are additions such as 60 new high-definition channels, faster Internet download speeds and the "Look Back" cable feature that allows customers to re-watch shows they missed.

In October, Time Warner Cable reported that its earnings fell slightly in the third quarter, to $356 million. In that same period, revenue increased about 4 percent, to $4.9 billion.

Time Warner Cable's number of residential video subscribers fell to 11.9 million, down from 12.4 million at the same time last year. Internet and voice subscriptions rose, however. Nationwide, Time Warner Cable is the second largest cable, Internet and voice provider, with more than 14 million subscribers in 28 states, behind Comcast.

For an introductory 12-month rate of $89.99 a month, Time Warner Cable offers its Triple Play cable TV, phone and Internet bundle, according to its website. Comcast offers a similar triple bundle for $99 a month.

Time Warner Cable and other providers of cable and Internet service have been getting into other businesses to boost revenue as people turn to services such as satellite TV, Hulu and Netflix to get their video fix. Comcast and Time Warner are both rolling out home security systems, hoping to build on their existing broadband connections to customers' homes.

Time Warner's system, called Intelligent Home, is debuting in Charlotte, New York and Southern California.

New York-based Time Warner Cable employs some 3,000 people in Charlotte. The Los Angeles Times contributed.