Combining Clearwire's enormous radio spectrum assets with industry giants AT&T ( T 0.27% ) or Verizon ( VZ 0.51% ) would never pass regulatory muster. T-Mobile USA and MetroPCS ( TMUS 1.75% ) are too busy completing their own merger to mess around with another large addition. Nobody else has the cash reserves required to settle the $4.3 billion total bill -- and Sprint holds an obvious advantage by dint of already owning about half of the target company. You'd be crazy to get into a bidding war with Sprint under these conditions.