EarthLink Network Inc. and Korean telecom giant SK Telecom Co. Ltd. announced details of their new $440 million joint venture, changing the company name to Helio Inc. and promising to take cellular service to a new level.

Helio, the Los Angeles-based venture formerly called SK-EarthLink LLC, is promising a new multimedia experience based on the new, faster third-generation wireless networks that are being rolled out domestically and will rival what’s being offered in Korea and other Asia countries.

Helio, which will sell handsets manufactured in South Korea exclusively for the service, will offer high-speed Internet access, music and video, in addition to phone service, in an attempt to remake how customers use their cell phones.

“The U.S. experience is really just about voice,” said Chief Executive Sky Dayton. “But if you go to Korea and walk down the street, the average person is using their mobile device to play games, watch TV, do video conferencing, listen to music and by the way, they also make phone calls.”

Helio is targeting 18- to 32-year-old, tech-savvy consumers and is joining a growing number of companies offering expanded cellular services. Walt Disney Co. recently announced it will be starting Disney Mobile, a service aimed at families.

Helio is set to launch next spring with Sprint PCS Group as a partner, but the the extent of that agreement was not revealed. However, Dayton said the service will run on Sprint PCS and Verizon Communication Inc.’s telecom networks. Pricing and service plans were not disclosed.

The company has 110 employees in its Westwood offices and is expanding. There also are another 200 contract employees and vendors, some working out of EarthLink’s Pasadena offices. “We’re hiring a person a day right now,” Dayton said.