Google's super-fast Internet service is heading for four more US metropolitan areas as the technology titan ramps up pressure on cable service giants. Google launched its Fiber program launched nearly five years ago will expand to 18 cities in the Atlanta, Charlotte, Nashville and Raleigh-Durham areas.

"We can't wait to see what people and businesses across the southeast US do with gigabit speeds," Google Fiber vice president Dennis Kish said in a blog post announcing the expansion Tuesday.

Google Fiber is already live in Kansas City, Provo and Austin.

Google is meanwhile working on a new generation of applications designed to capitalize on Internet speeds available using Fiber, but did not disclose details.

"Today, we aren't the only ones talking about gigabit broadband," Kish said.

"From the White House to main street, a chorus of new voices is standing up for speed."

In the meantime, media reports suggest that Google is getting ready to sell wireless telephone services directly to US consumers after reaching deals with carriers T-Mobile and Sprint.