An anonymous reader writes "The attempted merger between AT&T and T-Mobile has fallen on hard times amid antitrust concerns, but there's a potential silver lining for T-Mobile — one that would give them a boost over competitors anyway. Reuters reports that T-Mobile USA would be entitled to a hefty breakup fee including $3 billion in cash as well as spectrum and roaming agreements. 'In a research note, Moody's said that could also lead to a network sharing deal between the two companies, reasoning that it "would make sense given the spectrum that AT&T will have to cede to T-Mobile and the 3G roaming agreement between the two." That would make life especially hard for No. 3 U.S. carrier Sprint, which has been one of the most vocal opponents of the AT&T/T-Mobile deal, going so far as to file a lawsuit. ... Smaller rivals such as MetroPCS and Leap Wireless may be affected even more because T-Mobile is eyeing similar customer segments.'"