SYDNEY (Reuters) - American Airlines (AAL.O) warned airline passengers may eventually face higher ticket prices if oil prices remain high, prompting carriers to remove seats from the market. Oil prices have risen around 50 percent compared to the levels seen last year and that is putting pressure on airline profits. IATA, which represents about 280 airlines comprising 83 percent of global air traffic, has said that on Monday it will revise down its forecast for industry profitability this year due to higher oil, infrastructure and labor costs.