[caption id="attachment_86818" align="alignnone" width="500"] Uber is now offering residents in Marin and Napa counties the option of hired-car services. (image courtesy of Uber)[/caption]

NAPA -- San Francisco-based Uber Technologies is expanding again in the North Bay, this time into Napa County.

Uber, which contracts with freelance drivers using their own vehicles who are dispatched via notifications from its mobile application, recently entered Marin County and has said it would look to expand further into the North Bay. The company is now in 90 cities across the globe, from New York City to London to Sydney.

By entering into the Napa market, Uber said it hopes to provide a key transport link in Wine Country at a competitive price point through its three main offerings:  uberX, UberBlack and UberSUV, each designed to accommodate a range of needs, from more affordable to higher-end to small groups.

"From Napa to Yountville, Uber rides come in all shapes and sizes," the company said in a blog post late Thursday announcing the expansion.

The company has about 20 drivers signed up in Napa, where Uber is hoping to capitalize on the wine tourism and restaurant sectors. It made itself available during last year's BottleRock music festival in Napa, as well.

Uber and other ride-sharing services, like Lyft and Sidecar, have faced criticism, much of it from the existing taxi industry that has said  ride-sharing companies act as unlicensed taxis and limos and are subjected to less oversight. The California Public Utilities Commission recently said it would regulate the industry under a new category, Transportation Network Companies.

Uber drivers are independent contractors and must have insurance and clean driving records, the company said.

With Marin and Napa counties now on its roster, Uber said it will be keeping a close eye on Sonoma County for possible expansion.

"Sonoma County is definitely on our radar," said Spencer Rinkus, a company spokesman. "We want Uber to be accessible nearly everywhere people travel, so we're expanding into every region where there's consistent demand. We can't say when that will happen, but we're watching the area closely."

Uber's mobile app lets passengers find drivers in a given area, and all payment is made through smartphones. Uber said first-time users in Napa will get $15 off their first two rides.

The company has some 500 employees in the U.S. and abroad. Reuters reported that the company is generating about $200 million a year in revenue, excluding what it pays its drivers.