<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by pinniped:
Why would you do this? It's certainly not a violation of the airline's rules to buy a LAX-LHR and a LHR-BCN ticket: </font>
Actually, it is against the rules to do so on many airlines. You can not in your example use two round trip tickets from LAX to LHR and another from LHR to BCN on the same airline to save money on a LAX to BCN ticket. It's against most airline's rules to do so, which is why, if you are going to do it, you should do it on different airlines.