 Frontier Airlines parent Frontier Group Holdings Inc. ULCC, -11.20 issued a statement Tuesday to set the record straight about JetBlue Airways Corp.s JBLU, 1.62 comments regarding antitrust concerns that would be raised if it acquired Spirit Airlines Inc. SAVE, -7.95 The statement comes after JetBlue increased its bid to buy Spirit late Monday, as the air carrier tried to break up the merger deal between Frontier and Spirit, which was also sweetened late Friday. Frontier noted that JetBlue has said recently that Spirit was hiding behind false and misleading antitrust concerns to deny JetBlues buyout attempt. 