CONCORD, N.H. – Verizon Wireless has begun offering a new service to New England telephone customers that it says will allow for higher-speed access to the Internet from wireless devices.

The service promises to deliver Internet access at speeds comparable to dial-up modems for an extra $30 a month for phone subscribers.

Verizon is initially launching the service in only about 20 percent of its national service area, including Portland, Maine; a section of New Hampshire including Concord, Manchester, and Nashua; all of Rhode Island; and in Springfield, Worcester, and all of Massachusetts east of Worcester.

Verizon’s Express Network comes as Sprint PCS is preparing to offer a similar service in Boston this spring and AT&T Wireless and Cingular are planning to offer faster wireless data services within the next two years. Last year, VoiceStream launched “iStream”; Nextel said it plans to boost data speeds within the next year.

Verizon Wireless says its new service is a big improvement over existing wireless services, which reach only 14.4 kilobits per second.