The CEO of Canada's Laurentian Bank has resigned following a significant IT outage.

Rania Llewellyn left the company in the wake of IT issues during the mainframe maintenance update last week. The bank has named Eric Provost as president and CEO in replacement.

"We have experienced challenges recently and the board is confident that Eric will successfully focus the organization on our customer experience and operational effectiveness," said director and chair of the board Michael Boychuk.

The outage began during a planned maintenance period, and the bank told customers on Monday that their data remained secure "at all times," and that most of its services had been restored.

The exact cause of the problem - and the extent of the financial damage done - have not been shared.

The company will be reversing monthly service fees for the last month, will open on a federal holiday to resolve the issues, and will help those who missed payments due to the outage and thus saw their credit ratings suffer.

"Once the issues related to the outage are fully behind us, we will develop a new plan to ensure the sustained success of our bank," said new CEO Eric Provost.

"We will focus our efforts on renewing the trust of loyal customers while continuing our efforts to drive greater operational efficiency and growth in all our business lines."

Marcel Mclean, an analyst with TD Bank which covers Laurentian has speculated that the CEO change may also be motivated by "potential disagreements between management/board members." The company was previously conducting a review of its "strategic options" to sell the bank, but failed to secure a deal.

Outages can have significant impacts on banks and their customers, with people often left without access to their money. Earlier this year, Nigeria's Zenith Bank was hit by an outage after a fire broke out in its data center.

In September 2022, the UK's Co-operative Bank went offline during a widespread outage due to an "external Internet issue."