U.S. airlines shares rise as fares go up in July

** Shares of U.S. airlines rose after Consumer Price Index data showed rising airfare in July

** Data shows airline fares rose 4% in July vs 0.1% fall last month

** Jetblue Airways JBLU.O, American Airlines AAL.O up nearly 6%; United Airlines UAL.O, Delta Air Lines DAL.N up about 5%; Southwest Airlines LUV.N up 2.5%

** Airlines have been focusing on sales of premium seats amid an overall travel demand slump in the U.S.

** High margins and strong demand for premium seats are helping offset pullback in spending by price-sensitive customers

** YTD, Dow Jones U.S. airlines index fell 9.32%