Virgin Mobile USA (NYSE: VM), the MVNO which just reported its Q1 earnings earlier this week, is in talks with the much smaller and troubled MVNO Helio, we have learned, even as other PE and strategic players are still circling both the companies. Helio is now controlled by SK Telecom (NYSE: SKM), after Earthlink (NSDQ: ELNK) stopped making further investments, and has been looking at options to either exit or grow. For VMUSA, as we have mentioned, some PE players have been looking at investing in the company or buying it outright, and even if the VMUSA-Helio deal comes through, the two could use some extra cash.