The early bird gets the overhead baggage space -- at least on Southwest Airlines Co.

Dallas-based Southwest said on Wednesday it started charging passengers $10 each way to board flights before general check-in starts, but after premium passengers, including those flying Business Select.

The service, known as EarlyBird Check-in, is available for purchase starting on Wednesday for flights beginning on Thursday, September 3. The offering allows passengers to select seats and secure overhead bin space, said Southwest, which does not typically assign seats.

The fee will also create incremental revenue opportunities for Southwest, the low-cost carrier said.

Tough times in the airline industry have forced carriers such as Southwest to find new ways to drum up cash. In May, the airline started allowing some pets on board for a $75 fee and announced a $25 charge for unaccompanied minors.

Southwest has so far refused to charge passengers for bags, unlike most other major U.S. airlines.

(Reporting by Deepa Seetharaman; editing by Andre Grenon)