PHOENIX, April 19 (Reuters) - America West Airlines on Friday reported a $358.3 million first-quarter net loss mainly on accounting changes, joining other carriers in reporting huge losses made worse by weak demand and cheap fares following the Sept. 11 attacks. The unit of America West Holdings (AWA), the No. 8 U.S. carrier, said the loss amounted to $10.62 per share, as it took a $272 million write-down in adopting new goodwill accounting rules and $60 million pretax charges mainly for its fleet. "America West's first-quarter results reflect the severe economic downturn facing the airline industry," Chief Executive Douglas Parker said in a statement. Parker said the carrier has had an encouraging gradual month-to-month revenue improvement considering the industry environment. The carrier had a positive cash flow in March, typically one of its strongest cash flow months. America West, the only major carrier to apply for and accept federal loan guarantees, said total operating revenue fell 21.6 percent to $460 million in the first quarter. Excluding special charges, America West lost $47.6 million, or $1.41 per share. The carrier reported a net loss of $12.8 million, or 38 cents per share, a year ago. Analysts' loss estimates ranged from $1.40 to $1.60 per share for a mean of $1.50, according to research firm Thomson Financial/First Call. Shares of America West Holdings rose 4 cents to $5.30 Friday morning. The shares have risen about 50 percent since the start of the year and have outperformed the American Stock Exchange airline index (XAL) by about 32 percent since then. Pretax special charges included $39 million of value impairment for owned aircraft and engines, $10 million of fleet restructuring, $6 million of losses on aircraft sales and $5 million of restructuring-related fees. Unit revenue, a widely watched industry figure measured by passenger revenue per available seat mile, fell 8.2 percent in the quarter, the carrier said. Unit revenue fell 13.3 percent in the third quarter and 17.7 percent in the fourth quarter last year. Unit costs, measured by operating cost per available seat mile excluding special charges, fell 0.8 percent mainly on a steep drop in fuel prices, America West said. Unit costs rose 4.4 percent holding fuel prices constant. The carrier had a record quarter-end cash balance of $421 million and received about $390 million of net proceeds in January from a government-backed loan. America West also received a $34 million federal tax refund in February. America West cut business fares as much as 60 percent in late March, but does not rely on business travelers as a major source of revenue. America West said the new business fare structure had no material effect on first-quarter revenue. ©2002 Reuters Limited.