Looks like 340,000 UPS workers could go on strike next month after the shipping company and the Teamsters union failed to reach a deal on a contract renewal before negotiations ended Wednesday morning. The current contract ends July 31, and while that might seem like enough time for a settlement to be reached, CNN reports that "nervous" UPS customers are likely to move their business to competitors including FedEx and the US Postal Service by the end of this week. One expert who works in the shipping industry notes that after the last UPS strike in 1997, the shipping company got 90% of its business back after the strike ended, but this time—thanks to an increased number of competitors as well as those competitors getting increasingly competitive with their offerings—that number could drop to 70% if a deal isn't reached soon. More coverage: