Virgin Mobile USA today filed with the SEC for an IPO in which it would sell 27.5 million shares for $15 to $17 each, generating around $375 million for the company.

As RCR Wireless News' Kelly Hill notes, this is just one of series of steps the company has made towards an IPO. "The MVNO initially filed for a $100 million IPO in May, but in July amended its filing to $500 million," Hill writes.

According to Reuters' Sinead Carew and Sayantani Ghosh, the IPO would float 42.8 percent of Virgin Mobile, and would cut Sprint Nextel's stake in the MVNO enormously, from 47 percent to 17.2 percent. Similarly, Virgin Group's ownership would drop from 47 percent to 35.7 percent.

It's been a tough time for MVNOs lately (see Amp'd Mobile), but Virgin Mobile says it made a slight profit in the first half of this year. Still, I've gotta say I'm cynical - I can't believe any MVNO is likely to make enough money to justify this kind of investment...

More here from the AP ... more here from AFP ... more here from Cellular-News ... and more here from MarketWatch.