If you’ve had trouble booking an early-morning United Airlines flight to San Francisco due to lack of available seating, that might not be a problem after Aug. 15.

That’s because the airline will begin offering flights using larger Boeing 737 planes for the daily 6 a.m. runs from Fresno Yosemite International Airport to San Francisco International Airport.

Fresno is one of 10 cities — including Palm Springs, Burbank, Dallas, Kansas City and Sacramento — where the first flights of the morning to San Francisco will be done with larger planes.

In the case of Fresno Yosemite International Airport, SkyWest Airlines is contracted with United to provide United Express passenger service using its own 50-seat Canadair Regional Jet 200 aircraft, according to the company’s website.

Jonathan Guerin, a spokesman for Chicago-based United, said the larger plane can take 100 more passengers than SkyWest’s CRJ 200s.

“It’s one of the ways we are increasing the efficiency of our fleet,” he said, explaining that to do this, a United-owned — or “mainline” — 737 will leave San Francisco at 10 p.m. daily to head to the Fresno airport, where it will remain overnight and then head back to San Francisco in the morning.

“Strong demand for business and leisure travel between FAT [Fresno] and SFO [San Francisco] make the 6 a.m. departure time from FAT ideal for customers to arrive in SFO in the morning,” Guerin said in an email.

That is the busiest time at Fresno Yosemite and other West Coast Airports, as passengers here tend to want to get their travel started early, said Kevin Meikle, director of aviation for the City of Fresno.

“We’re excited. It’s a great move,” he said of United “upgauging” (switching to a larger plane) its early-morning flights.

“Any time an airline does this it’s a benefit to the traveling public, so I think its great.”

As for United Express flights in and out of Fresno, Utah-based SkyWest will continue providing them using its planes, said Marissa Snow, a company spokeswoman who referred further questions to United.

In the company’s press release, United also announced that starting in August it will increase the number of daily flights between San Francisco and Seattle, Albuquerque, Baltimore, Indianapolis, Kansas City, Nashville, Philadelphia and Portland by at least two, and up to 10.