A federal judge rejected Hawaiian Airlines' request to ban go!, the new interisland airline, from operating for one year, but not before criticizing the conduct of go!'s parent company.

U.S. Bankruptcy Judge Robert Faris yesterday said that Hawaiian's request to prohibit go! and its Phoenix-based parent Mesa Air Group from selling interisland tickets for a year "would likely terminate Mesa's participation in the interisland market."

Hawaiian sued Mesa in February, alleging the low-cost carrier used confidential information obtained during Hawaiian's recent bankruptcy to help plan go!'s operations. Mesa was one of several companies that looked at investing in Hawaiian to help it emerge from bankruptcy.

Faris said Mesa "probably breached the confidentiality agreement" by failing to return or destroy material it received from Hawaiian in a timely manner. But Faris also said Hawaiian didn't identify "any irreparable harm" as a result of Mesa's action.

While denying Hawaiian's request to halt go!'s operations, Faris also criticized Mesa for its alleged attempt to drive out one of its competitors.

The judge cited a May 2005 e-mail by the airline's chief financial officer, Peter Murnane, in which Murnane discussed giving Aloha Airlines, which was in bankruptcy last year, a final push to drive it out of business.

"At least at one time, Mesa hoped to drive Aloha out of business," Faris said. "Although the evidence raises real doubts about the propriety of Mesa's conduct, I conclude that Hawaiian has not met the stringent standard for a preliminary injunction (to halt go!'s ticket sales for a year)."

Jonathan Ornstein, Mesa's chief executive officer, called Faris' ruling "a big win for the people of Hawai'i and for low fares."

Ornstein, whose company countersued Hawaiian, hinted that he may offer to drop his suit if Hawaiian would do the same with its suit.

Ornstein would not comment on Murnane's e-mail, saying the matter is still a subject of litigation. In the past, Ornstein has said that e-mail was taken out of context and that Mesa's business plan had always envisioned having three major players in the interisland market.

"I think that most people will see through (Hawaiian's suit) for what it is, which is a blatant attempt to stifle competition and raise fares back to where they were before we entered the market," Ornstein said.

Mark Dunkerley, Hawaiian's chief executive officer, said he's confident that Hawaiian will eventually succeed in its lawsuit against Mesa, which seeks monetary damages for breaching its confidentiality agreement with Hawaiian. He also believes that Hawaiian will succeed in getting a permanent injunction against Mesa's entry in the interisland market. That part of the case is scheduled for trial in April.

Dunkerley said that Faris' ruling raised a number of questions about Mesa's credibility, including testimony from Mesa's chief financial officer "about Mesa's desire to put Aloha Airlines out of business."

"The judge's ruling reinforces our conviction that, rather than increasing competition in the Hawai'i island market, Mesa is using deceptive practices, size and clout to injure competitors and destroy competition," Dunkerley said. "Let us be clear that Mesa is Goliath to Hawaiian's David in this fight."

Aloha Airlines spokesman Stu Glauberman said the airline did not want to comment on the decision.

Mesa launched interisland carrier go! on June 9 and triggered a fare war when it introduced $39 one-way interisland tickets on its first day of business. Both Hawaiian and Aloha matched the fare.

Since then, Mesa lowered one-way fares to $29 on several occasions, before dropping them to as low as $19 last month. Aloha and Hawaiian matched go!'s fares each time a discount was announced.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.