Travel Aug. 13, 2008 - 06:27AM JST ( 6 )

FORT WORTH, Texas —

It will soon cost you $50 to upgrade from economy coach on U.S. trips aboard American Airlines. American, which invented the mileage program 25 years ago, has notified customers that it will raise fees and miles needed for upgrades and free trips.

Under changes that take effect Oct 1, an upgrade from economy coach on a one-way domestic flight will cost $50, plus the previously required 15,000 miles. A round trip upgrade would be $100 and 30,000 miles.

Fees for upgrades were also raised on international flights, and some mileage requirements for earning round-trip tickets were also boosted. The airline told members of its AAdvantage frequent-flier program of the changes in an email message.

American’s moves follow changes at Delta Air Lines Inc’s mileage program earlier this month.

Delta said it would give frequent fliers a guaranteed ability to redeem miles for a free trip but sometimes at the cost of many more miles. Under a new three-tier program, fliers who spend more miles will get a better shot at winning one of the limited number of seats set aside for reward tickets.

Airlines are raising fares and a variety of fees to cover higher jet fuel costs, but most U.S. carriers are still losing money. American parent AMR Corp lost nearly $1.8 billion in the first six months of this year after earning profits in 2006 and 2007.

American is raising the fee for a one-way upgrade from the U.S. to Europe, China, Japan, Argentina, Brazil, Bolivia, Chile or Uruguay to $350, from $300. Upgrading to India? That’ll be $400. All those trips still require 25,000 miles except India, still 40,000.

American also boosted the number of miles needed to upgrade full-fare coach seats to business- or first-class on some routes. On flights to Hawaii, Mexico or the Caribbean, it’ll take 8,000 miles instead of 5,000, and Europe will be 15,000 miles, up from 10,000.

Mileage requirements for some round-trip awards were also raised. For example, a last-minute round trip in coach to Europe will cost 120,000 miles, up from 100,000, but those who plan in advance might still get a seat for the current 40,000 miles.

American spokeswoman Marcy Letourneau said the company was raising the fees because “the disparity between an economy seat and a business seat is too great to be offset just by miles.”

Letourneau said customers still value the reward program, even with higher fees. “We have many loyal customers, and we hope they remain loyal,” she said.

American’s AAdvantage program was revolutionary when it was introduced in the 1980s, and it is often credited with helping build loyalty to the carrier.

Could more changes be on the way for frequent fliers?

In a footnote to the email sent to customers, American said it reserves the right to change the frequent-flier program rules at any time, without notice.

Wire reports