Sky Dayton, the founder and chief executive of Helio LLC, is stepping down as CEO to become chairman of the youth-oriented cell-phone provider, the Associated Press is reporting.

Dayton is well-recognized as an industry visionary, having started not only Helio but the top-tier ISP Earthlink. However, Helio has struggled form the outset; while it offers nice mobile media-focused handsets and an array of high-end data plans, it has struggled to reach even 200,000 subscribers in the three years it's been around. Not only that, but other MVNOs following the same business model of licensing bandwidth from the major carriers -- including Amp'd Mobile, Disney Mobile, and Mobile ESPN -- have all failed.

Back in September, SK Telecom invested an additional $270 million in Helio.

Helio CEO Leaves Job to President [AP via 1010 WINS]