iPhone Could Crunch Sprint

As Sprint's (S Quote) struggles continue, some see an even steeper fall ahead.

But the Reston, Va., phone company's next wound may not even be self-inflicted. Industry watchers and investors say the next looming threat to Sprint comes from the hotly anticipated iPhone from Apple (AAPL Quote).

If the iPod-inspired phone has anything near the success that some observers expect, AT&T's (T Quote) exclusive arrangement to sell the phone will ring up big subscriber wins. The way some observers see it, many of those new AT&T customers will likely be coming from Sprint.

Sprint is the most vulnerable because it has one of the biggest groups of heavy data users, notes one investor who has no position. ...