Hawaiian Airlines announced a major expansion of its interisland service with the addition of four Boeing 717-200 jets.

Hawaiian, the state's largest carrier, said the additional aircraft increases its interisland fleet to 15 Boeing 717 aircraft.

The expansion will help fill the void left by Aloha Airlines, whose March 31 shutdown eliminated 700 weekly flights and about 88,000 passenger seats a week from the interisland market.

"This substantial investment in more interisland aircraft reaffirms Hawaiian's long-term commitment to serving the people of Hawai'i," said Mark Dunkerley, Hawaiian's Chief Executive Officer.

Two of the jets — which are being acquired on long-term leases from Boeing Capital Corp. — will begin flying in September. The remaining aircraft will start flying in November and December.

Hawaiian did not say how many more flights it plans to operate with the new aircraft. But the company did say that it plans to add flights during periods of the day that customers prefer to travel.

Shares of Hawaiian closed at $7.16 on the Nasdaq market yesterday, down 6 cents.

Hawaiian, which operates more than 1,000 flights a week, expanded its service earlier this year in wake of Aloha's demise by adding an extra 717-200 jet. The 717 aircraft had been used as a "spare" in case of a delayed flight.

Hawaiian also added a larger 767-300 wide-body jet for its interisland service.

The Boeing 767 aircraft, which seats 252 to 264 passengers, is usually used for Hawaiian's trans-Pacific service.

The 717 aircraft seats 123 passengers.

Hawaiian said it plans to hire additional flight crew and ground staff for the expansion.

The airline said it recently hired 230 new workers, mostly former Aloha employees, and is looking to fill another 150 positions, including pilots, flight attendants, maintenance technicians, contract service and line service positions.

The addition of planes comes as Hawaiian plans a major overhaul of its trans-Pacific fleet.

Earlier this year, the company finalized a $4.4 billion acquisition of up to 24 new Airbus jets.

The Airbus planes — which will be delivered between 20012 and 2020 — will replace the carrier's wide-body fleet of 18 Boeing 767-200 planes and will allow Hawaiian to fly to destinations in Asia, Europe and South America.