= American Airlines says September bookings weaker = = Friday September 13, 5:54 PM EDT = WASHINGTON, Sept 13 (Reuters) - American Airlines, in another sign of con= tinuing industry financial problems, said on Friday that September bookin= gs were weaker than expected and that unit costs so far this quarter were= in line with an expected decline. In a filing with the Securities and Exchange Commission, the world's bigg= est airline, a unit of AMR Corp. (AMR), also said that its fuel costs hav= e risen and remain "persistently high." The airline also said that its unit costs, or costs per available seat mi= le, were in line with previous expectations of a 3.5 percent decline for = the third quarter from year-ago levels. American said bookings for September were generally weaker than expected,= especially in the weeks around the anniversary of the Sept. 11, 2001, hi= jack attacks. = =A92002 Reuters Limited. = Roger EWROPS