Continental did order the A340 but cancelled before delivery. One model manufacturer even produced a line of the A340 in Conti's meatball livery which has since become mucho collectable!
Air Canada flies both the A340 and 330, Transat the 330. TWA were also looking to buy some A330 at one stage but that never happened either. US based lessors obviously own quite a few of all versions (including Boeing who took those Singapore A340s in trade for a 777 deal)