Mesa Air Group Inc. must pay $3.9 million in legal fees and costs in addition to $80 million in damages awarded to rival Hawaiian Airlines Inc. over misuse of the carrier's confidential information, a judge ruled.

Mesa is the parent of interisland carrier go!.

U.S. Bankruptcy Judge Robert Faris ruled that Hawaiian officials were entitled to recoup more than $3.6 million in fees and more than $275,000 in costs from Mesa in connection with claims that Mesa used deceptive practices to gain access to Hawaiian's passenger and pricing data while the Honolulu-based airline was under bankruptcy protection. Faris awarded Hawaiian $80 million in damages in October.

"My independent review of billing records convinces me" that Hawaiian Air's fee request was reasonable, Faris said in an 11-page ruling Tuesday.

Brian Gilman, Mesa's general counsel, wasn't available for comment on Faris' ruling.

Hawaiian's executives accused Mesa officials of posing as investors to gain access to confidential information they could use to set up go!, an island-hopping competitor. Phoenix-based Mesa breached a confidentiality agreement it signed to view the data, Hawaiian executives contend in the suit.