Virgin Mobile USA has filed plans with the SEC to issue up to $100 million in stock, taking public the venture between Sprint and the U.K.’s Virgin Group.

Virgin Mobile has 4.9 million U.S. prepaid subscribers in it mobile virtual network operator business, accounting for the majority of wholesale subscribers on Sprint’s network. While $100 million is a small amount for a wireless company IPO, Virgin Mobile doesn’t have a network to invest in. But capital raised from the initial public offering would allow 50-50 owners Sprint and Virgin to recoup some of their initial investment as well as pay off Virgin Mobile’s debt. While it has been operating since 2002, Virgin Mobile has yet to turn a profit, according to the SEC filing.

Virgin, which is controlled by U.K. media icon Richard Branson, may be using the IPO as a way to ween Sprint of the partnership. When the MVNO launched in 2002, Sprint had no prepaid service, nor did it focus closely on the youth market Virgin appeals to. However, after its acquisition of Nextel, Sprint gained a robust pre-paid service with Boost Mobile, which targets the same teenage segment as Virgin. Sprint hasn’t neglected either business, however. In fact, all of Sprint’s subscriber growth in the last two quarters has come from new Boost customers and new wholesale customers—presumably brought by Virgin.