It's back to $19.

In June when go!, the new interisland airline run by Phoenix-based Mesa Air Group, began operations, it offered introductory one-way fares to the Neighbor Islands for $19.

Today, go! is back at it.

The $19 fares go on sale today and are good for travel through Feb. 28. Tickets must be purchased by Sept. 30. Restrictions apply to the go! fares, and the company did not specify how many $19 tickets would be available.

The new cut-rate fares will likely be matched by competitors Aloha Airlines and Hawaiian Airlines.

When go! last offered a $19 fare in June, it was matched by Hawaiian Airlines; Aloha Airlines countered by giving away 1,000 tickets.

Hawaiian and Aloha were not contacted for comment yesterday because go! asked that news of its $19 fare not be released until 2 a.m.

"Our customers tell us that without go!, low fares would not be available to the people of Hawai'i," Jonathan Ornstein, chief executive officer of Mesa Air Group, said in a news release.

Go! touched off a price war when it opened for business in Hawai'i on June 9. Lower interisland fares since then appear to be boosting travel by local residents, many of whom had cut back on Neighbor Island trips when one-way prices jumped to $80 or more after Sept. 11.

"I'm anxious to try the new airline," said local attorney Shelton Jim On, who flies to the Neighbor Islands every other week for his business.

Jim On said he is a member of Hawaiian Airlines' frequent flier plan.

After its earlier $19 sale, go! offered $29 fares on several occasions — and each time it was immediately matched by Aloha and Hawaiian. Last week, go! dropped ticket prices for travel through Oct. 31 to $28, which again was immediately matched by Aloha and Hawaiian.

The fare war comes as the state's two dominant carriers have emerged from recent financial troubles. Hawaiian Airlines emerged from bankruptcy protection in June 2005 while Aloha exited bankruptcy reorganization in February.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.