The number of airline passenger seats from the Mainland is expected to rise 7.8 percent this quarter compared with a year earlier.

The state Department of Business, Economic Development and Tourism said the passenger capacity on Mainland to Hawai'i flights will likely rise to about 2 million seats during the July-to-September period.

The increased capacity from the U.S. Mainland will offset an 11.3 percent decline in air capacity from Japan. Overall westbound and eastbound travel to Hawai'i is expected to increase by 4.1 percent in the quarter to about 2.7 million seats, DBEDT said.

"The increased lift is encouraging for the visitor industry and people in Hawai'i as a whole because it makes travel that much easier," said Murray Towill, president of the 180-member Hawaii Hotel & Lodging Association.

DBEDT's forecast comes as ATA Airlines announced Tuesday that it will add 50 seats a day on its Hilo-to-Oakland route starting Aug. 4.

Meanwhile, Hawaiian Airlines has said that it will operate year-round daily flights between Maui and San Diego starting Sept. 6.

The Maui-to-San Diego service, currently a daily flight only during the summer season, is part of Hawaiian's plan to add 21 roundtrip flights to the West Coast later this fall.

According to DBEDT, seating capacity in Hawai'i's largest gateway, Los Angeles, will increase by 2.9 percent while capacity from San Francisco, the state's second-largest gateway, will likely drop by 19.1 percent.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.