FiOS runs over a fiber network that goes all the way to subscribers' homes and businesses, avoiding the lower capacity of copper wires. The theoretical capacity of a strand of fiber is almost limitless, and Verizon has gradually increased the speeds it offers. The 300Mbps Internet service will be available by itself or as part of bundles with TV and voice.

Also next month, Verizon will increase the upstream speeds on two of its tiers, introduce a new 75Mbps/35Mbps tier, and stop offering its 35Mbps and 25Mbps tiers for new subscribers. Verizon's 50Mbps plan will go from 20Mbps to 25Mbps upstream, and its 150Mbps service will go from 35Mbps to 65Mbps upstream.

Consumers' growing use of over-the-top Internet video programming, as well as gaming, audio streaming and online backup services, created the demand for the upgraded speeds, Verizon said. It recommends the 300Mbps and 150Mbps services for households with five or more Internet-connected users who watch HD and standard-definition video on a variety of devices.

FiOS is available to more than 13.7 million Verizon customers in parts of nine Northeast and mid-Atlantic states, as well as the District of Columbia and parts of Florida, Texas and California, according to Verizon. The service has more than 5 million customers, most of whom buy a bundled plan, Verizon spokesman Bob Elek said. A majority of FiOS customers will be able to sign up for the 300Mbps service starting in June, Elek said.