MINNEAPOLIS — The chairwoman of the authority overseeing the Minnesota Vikings’ stadium resigned Thursday after weeks of criticism over the questionable use of luxury suites by officials’ family and friends.

Michelle Kelm-Helgen resigned Thursday in a letter, saying it was in the public interest for her to step down from the Minnesota Sports Facilities Authority.

“If I could go back and start over again, MSFA would have had a public discussion on the use of these suites and forbid the use of them by family and friends from the start,” Kelm-Helgen wrote.

A recent legislative audit found that nearly half of the tickets for a pair of suites controlled by the stadium authority were issued to friends and family of top officials.

No state laws were broken, but the auditor’s report said the marketing purpose of inviting friends, family and certain government employees to games and special events wasn’t clear. The report said the authority went against a “core ethical principle.”

Republican legislators have been pursuing major changes to the authority structure.

Kelm-Helgen, an appointee of Democratic Gov. Mark Dayton, spent years helping steer construction of the $1.1 billion stadium that just hosted its first NFL season.

Kelm-Helgen repeatedly apologized to legislators during a hearing on the audit. But she and authority executive director Ted Mondale also defended the practice as commonplace among stadiums around the country.

Several Democratic public officials paid back the authority $200 or more for previous games after the Star Tribune first wrote about the use of the suites by family and friends.