NEW YORK, AUG. 24 -- Some major U.S. airlines said today they are considering raising discount fares to match moves last week by American Airlines and Delta Air Lines.

The carriers said they were waiting to see whether Texas Air Corp. -- the industry's price leader with about 20 percent of the U.S. market -- would follow proposed increases floated by American and Delta.

A similar hike by Houston-based Texas Air, which owns Continental Airlines and Eastern Airlines, could prompt other airlines to follow suit.

"That's always the big clincher," United Airlines spokesman Matthew Gonring said, referring to Texas Air's influence on fares.

United, based in Chicago, is a subsidiary of Allegis Corp., which also owns hotel chains and automobile rental businesses.

Texas Air, in turn, is still studying the proposed fare increases by American and Delta, Texas Air spokesman Richard Scott said.

Decisions could be made later this week, the airlines said.

The American and Delta proposals, which would affect tickets purchased on or after Sept. 8, would increase some fares by $10 to $20 each way.

Both airlines admit they are waiting to see whether the increases are matched before putting them into effect.

"Basically, we haven't made a decision yet," American Airlines spokesman Steve McGregor said. "In this business you look very closely at what the competition is doing."

Both American and Delta would increase the advance-purchase requirement on the deeply discounted fares to 30 days from the current seven-day period.

Under Atlanta-based Delta's plan, discount fares would be raised by $10 to $20 each way, to compensate for a cut in the cancellation penalty to 50 percent from 100 percent for tickets purchased 30 days in advance.

There would be a 25 percent penalty for 14-day advance sales and a 10 percent penalty for seven-day advance sales.

American, based in Dallas, would introduce a 14-day advance-purchase fare with a 50 percent cancellation fee, which would run about $40 each way above the 30-day discounted fare.

That represents an increase of about $10 over current fares with a 50 percent penalty, according to American