For American business travelers, short regional routes between mid-size cities are especially important, because they allow for easy access to clients at affordable rates. Now facing slimmer profit margins, many carriers are beginning to shift away from the routes.

According to USA Today, several of the larger airlines are looking to downsize or sell off their regional carriers. Delta, whose regional flights are handled by Comair, has announced that it will cut its 99 regional jets down to 44 in the near future. According to the company, travelers will only see a slight downsize in routes because most of the planes are already out of service, but some of the other planes are from routes the company has deemed unprofitable.

Meanwhile, as the result of an investigation into the merger between Continental and United, it was revealed that the company has contemplated closing its Cleveland hub in the event of a drop in profits in the near future.

Across the board, companies are downsizing regional flights, as the high fuel prices make the small jets nearly as costly to operate as their bigger brethren.

“The era in which the economics allowed small jets to be leased and operated profitably on regional routes is over,” said industry consultant Mike Boyd. “There’ll still be some out there in service, but the era of 50-seat and smaller jets is over.”

In addition to downsizing, it is publicly known that both Delta and American Airlines are attempting to sell off their regional subsidiaries.