The entry of a new carrier into the interisland market contributed to go! airline's loss in the latest quarter.

Go! posted an operating loss of $2.1 million during the three months ending March 31 after reporting its first-ever operating profit in the previous quarter.

The results came on operating revenues of $9.6 million, which was up from the year-earlier's $7.2 million.

The airline, a unit of Phoenix-based Mesa Air Group, attributed the loss to the slump in tourism and the entry of Indianapolis-based Republic Airways into the interisland market through its Mokulele Airlines affiliate.

"We were profitable at go! the quarter before. This quarter we were not," Mesa CEO Jonathan Ornstein said in a conference call with investors.

"As you know, we have additional competition there as a result of Republic's entrance into the marketplace."

Shares of Mesa rose 7/10ths of a cent to 16.7 cents on the Nasdaq market yesterday.

In February, go! posted an operating profit of $500,000 for its fiscal first quarter due to lower fuel costs and increased passenger revenue due in part to the March 31, 2008, shutdown of Aloha Airlines.

Mesa, meanwhile, posted a pretax operating profit of $27.2 million. But that was erased by $64.5 million in income tax expenses that the company recorded during the quarter.

Overall, the company had a net, after-tax loss of $37.3 million.

In November, Republic and Kona-based Mokulele Airlines launched a new, low-fare interisland service using 70-seat Embraer 170 aircraft operated by Republic.

Republic assumed a controlling stake in the venture in March and replaced Mokulele CEO Bill Boyer with one of its longtime executives.