Southwest Lining Up New Flights Out of O.C. : Airlines: It seeks to offer 15 trips from John Wayne Airport to San Jose and Oakland, a move that could lower fares.

In a move that could significantly lower fares to the Bay Area and Silicon Valley, Southwest Airlines said it wants to operate its 15 new flights from Orange County’s John Wayne Airport exclusively to San Jose and Oakland.

But both airport and airline officials caution that the flight list proposed by the airline is likely to change. The new flights are scheduled to begin May 26, just in time for the summer holiday period.

Dallas-based Southwest said it plans to offer seven daily flights to Oakland and eight flights to San Jose. The only exceptions would be one of the evening Oakland flights would not operate on Saturdays and an early morning flight to San Jose would not operate on Sundays.

The schedule was filed with John Wayne Airport as a requirement to begin operation. The way for Southwest to fly into Orange County was paved recently with its purchase of Morris Air Service, another low-cost, low-fare carrier. Southwest’s proposed schedule indicates that it plans to maintain what were Morris’ two daily flights to Salt Lake City, which now have an unrestricted fare of $119 one way.

The arrival of Southwest has been long awaited because air fares often drop for routes where it begins to compete. Southwest, with some of the lowest operating costs in the airline industry, has thrived by offering low fares on short-haul trips.

Southwest Chairman Herb Kelleher said in a recent interview with The Times that one of the reasons he wanted to acquire Morris Air was to speed up Southwest’s entry into the Orange County market.

While Southwest has not provided any clues about the fares it will charge, a spokeswoman said that it will likely offer the same $69 anytime one-way fare to any California destination that it has offered from other Southland airports.

Its major competition would include Alaska Airlines, which offers a $99 anytime one-way weekday fare to Oakland on its five flights, and American Airlines, which services San Jose with eight weekday daily flights and an unrestricted one-way fare of $119.

“Prices are going to drop, specifically to San Jose and probably to Oakland as well,” said Thomas Nulty, president of Associated Travel in Santa Ana, one of the nation’s largest travel agencies.

An American Airlines spokesman in Dallas said Wednesday that his airline may pull out of the route to avoid competing. Southwest “is really tough to compete with on price, no question” and “we may not be there very long,” spokesman Marty Hires said.

If that happens, Nulty said it could leave room for another low-cost carrier, like Reno Air, to come in and grab up American’s unused slots.

As for Alaska, “they will probably continue in that market because their real interest lies in traffic beyond Oakland,” such as business travelers continuing to the Pacific Northwest, Nulty said.

Louis C. Cancelmi, a spokesman for Alaska Airlines in Seattle, said his company competes with Southwest on other routes, offering the same low fares with more frills.

“We have gone through an exhaustive process . . . with the assumption that low prices are going to be with us for a long time,” Cancelmi said. “As a result of that, we have made many changes, changes that allow us to significantly lower our operating costs. So by virtue of our lower costs, we can compete with anything anybody offers.”

Times staff writer Jesus Sanchez contributed to this report.