Delta’s $10 fare hike may not stick

Delta Air Lines Inc., the No. 3 U.S. carrier, raised round-trip fares on domestic flights by $10 to offset rising costs, but it was unclear whether the increase would hold as demand softens.

The test of pricing power comes at the start of the typically weak autumn travel period, when demand generally falls off.

“It is unusual to see attempted increases in this traditionally slower travel period,” said Rick Seaney, chief executive of FareCompare.com. “This time period historically has been filled with sales, not increases.”