JetBlue Competitor is a term used to describe three major airlines that compete with JetBlue. DELTA (5 letters) is an American airline that was founded in 1924 and is one of the oldest airlines in the world. UNITED (6 letters) is an American airline that was founded in 1926 and is the world's third-largest airline. TED (3 letters) is a low-cost airline owned by UNITED Airlines that operates mainly in the UNITED States.