Charter Communications said Monday that it is accelerating the rollout of its telephone service, launching the product in seven new markets and expanding the service in seven markets.

With the addition of the new markets, the number of households able to get Charter’s phone service increases by 1 million to nearly 4 million, the company said. The markets include Long Beach, Calif.; Willimantic and Newtown, Conn.; Chicopee, Mass.; Blount County and Jackson, Tenn.; and Gwinnett County, Ga.

The company also expanded its phone service in markets where the product was already available. Those communities include Sturgeon Bay, Wausau and Northeast, Wis.; Bristol, Va.; Asheville, N.C.; and Moreno and Adelanto, Calif.

As of March 31, Charter said it is servicing a total of 191,000 phone customers. Charter has just under 6 million subscribers.

Launching a telephone service has been an important strategy for the nation’s cable operators, which are locked in a pitch battle for subscribers with satellite companies. Traditional telephone companies are likely to become a competitor soon as they introduce a television product that is distributed over fiber-optic wires.

By offering a so-called triple-play of products-video, high-speed Internet and telephone services-cable operators are discovering they can hold on to customers in the face of stiffening competition.

Charter, for its part, has been slow to deploy its phone product, in part because the company is saddled with more than $19 billion in debt, which has hindered its ability to compete more effectively. However, the company has indicated recently that it is a priority for it to offer a triple-play package.