Sun Country Airlines, the Mendota Heights-based carrier that filed for bankruptcy protection amid a fraud investigation of its parent company, told a judge it owes $3.97 million to its 20 biggest unsecured creditors.

Delta Airlines has a claim for $950,000 and the Metropolitan Airports Commission in Minneapolis one for $1.48 million, according to papers filed Thursday in U.S. Bankruptcy Court in St. Paul. Unsecured claims are among the least likely to be paid in such cases.

Sun Country, which leases its nine planes, filed a Chapter 11 petition Monday after it couldn't get a $7 million short-term loan from its owner, Petters Group Worldwide LLC. The company's assets were frozen after its founder, Tom Petters, was arrested and accused of masterminding a $3 billion fraud.

"It was a shock to everyone," Sun Country spokeswoman Heidi Bausch said Thursday in a phone interview, referring to events at Petters Group. "All we know is what's in the papers. When it came out that day, it was a big blow to all of us."

Petters Group, owner of the photography company Polaroid, was raided Sept. 24 by the Federal Bureau of Investigation. Executives of the Minnetonka -based company duped at least 20 investors including some hedge funds with a lending scheme linked to phony electronics deals, prosecutors say.

A federal magistrate judge in St. Paul Wednesday denied bail for Petters, saying he "is facing the substantial risk of a very, very long prison sentence, perhaps the rest of his life" and is a flight risk.