ST. PAUL, Minn. - The chief of Minnesota's health insurance exchange has resigned abruptly after facing criticism over the rollout and a questionably timed vacation.

April Todd-Malmlov submitted her resignation Tuesday evening during a closed session of MNsure's governing board. She had been under increasing pressure over insurance sign-up problems. She also failed to get a vote of confidence from Democratic Gov. Mark Dayton last week.

She was a key figure in Minnesota's adaptation to the federal health overhaul since 2011. But after the Oct. 1 enrollment launch, MNsure's website encountered technical issues. A backup call center didn't fare much better.

Questions over Todd-Malmlov's leadership ramped up after disclosure of an extended trip to Costa Rica in late November, as critical insurance enrollment deadlines neared and issues were unresolved.

The MNsure Board has named Scott Leitz as Interim Executive Officer. He will oversee operational improvements to ensure the exchange works for Minnesotans and address the organization's long-range planning needs, officials said.

MNsure Board Chair Brian Beutner explained the new role and expressed confidence in Leitz.

"The Board believes the organization is at a stage where it needs a CEO to manage both MNsure's current challenges and position it for greater success in the future. Scott has been a proven leader at the Department of Human Services where he has managed a large and complex organization effectively."

Leitz says that his focus will be on partnering with health plans to make it easier for individuals to enroll in coverage and have insurance beginning Jan. 1.

"MNsure must do better. If there are problems or mistakes, we will acknowledge them and fix them," said Leitz. "I look forward to working with MNsure's talented team to make MNsure work for the people of Minnesota."

MNsure will hold a news conference to discuss the changes on Wednesday.