1.   But airline mergers historically have been fraught with problems ranging from operational glitches and service problems to labor strife.

2.   In addition, investors should keep a watchful eye on potential operational glitches.

3.   Many also complained of bulky telephones, operational glitches and expensive service.

4.   Speculation that Mobil Corp. will shut its Joliet, Illinois, refinery because of a fire or operational glitch also boosted prices, traders said.

5.   Traders said speculation that a fire or operational glitch at an Exxon Corp. refinery in Texas or Louisiana helped send oil prices rocketing.