By the end of this year, United, Delta and American Airlines will all have lie-flat seats in business-class sections. The move comes as a way to compete for corporate fliers who take transcontinental flights. "There are a couple of groups that represent a disproportionately large number of premium business travelers. Financial services, consultants, independent business executives and a few other industries like entertainment," said airline analyst Henry Harteveldt. "Those industries pay for premium cabin seats. That is the battle. That is where the profit is and that is who the big three airlines, United, Delta and American, are battling it out to win."