NASHVILLE (AP) - Comcast says it is bringing its super-fast Internet service to Nashville, but won't say how much it will cost to install or subscribe.

The company announced Wednesday it will offer residential customers fiber optic service of two gigabits per second - or twice the speed of what is currently offered by some municipal electric providers and by Google. The tech giant's high-speed Internet service, Google Fiber, earlier this year announced it will expand to four metro areas in the southeastern U.S., including Nashville.

Comcast previously announced it will offer its Gigabit Pro service in Chattanooga, Atlanta and in Florida and California. The company says the service will roll out to 18 million homes by the end of this year.

Comcast has been among cable TV and Internet providers fighting the expansion of municipal broadband in cities like Chattanooga. The Federal Communications Commission voted in March to override state laws blocking the expansion of municipal broadband.

But state lawmakers this year punted on legislation seeking to bring Tennessee into line with the FCC ruling, and state Attorney General Herbert Slatery has filed a legal challenge with the 6th U.S. Circuit Court of Appeals, arguing that the FCC has "unlawfully inserted itself between the state of Tennessee and the state's own subdivisions."

Google Fiber in its current markets waives a $300 construction fee for customers who commit to a full year of service.

Comcast in its release said that two-gigabit service will be available to homes "within close proximity" of its existing fiber network, and that the upgrade will require professional-grade equipment to be installed. A spokeswoman said pricing will be made public closer to when the service is launched later this month.

AT&T has also said it plans to bring gigabit-speed service to Nashville, but has not said when.

Through a combination of political will and federal stimulus money, Chattanooga became the first U.S. city to broadly offer a gigabit per second internet speeds - nearly 50 times the national broadband average.

According to the FCC, the average broadband speed in 2013 was 21.2 megabits per second. A gigabit equals 1,000 megabits.