Federal regulators have given Thrivent Financial for Lutherans the final green light to turn its bank into a not-for-profit credit union, an unusual change that creates one of the largest faith-based credit unions in the country.

The official conversion will take place this coming weekend, Thrivent said Monday, with Thrivent Financial Bank's two branches in Minneapolis and Appleton, Wis., opening Dec. 3 as Thrivent Federal Credit Union. The website will change Saturday.

All Thrivent bank clients -- more than 46,000 as of October -- will become member-owners of the new credit union when they transfer their accounts. The credit union will have nearly $500 million in assets.

The bank, meanwhile, is changing its name and charter to become a limited purpose, non-depository trust called Thrivent Trust Co., which will have $600 million in assets under management and continue to be regulated by the Office of the Comptroller of the Currency (OCC).

"It's good to see the light at the end of the tunnel," said Todd Sipe, head of Thrivent's bank and the credit union's new president and CEO.

In an interview Monday, Sipe said that Mike Haglin, a division vice president for Thrivent Financial for Lutherans, will serve as chairman of the credit union's board.

Thrivent received the final go-ahead in a written order from the OCC and the Federal Deposit Insurance Corp. in mid-November, Sipe said. The credit union's main regulator now will be the National Credit Union Administration.

Thrivent, a Minneapolis-based fraternal benefit society, is part of an exodus from banking after the 2010 passage of the Dodd-Frank Act, which intensified bank regulation and requirements.

To avoid the additional requirements, a number of large life insurance companies such as Prudential Financial Inc. have taken steps in recent years to ditch their designation as savings and loan holding companies by disposing of their bank units in some fashion and focusing instead on trust services, according to SNL Financial. Prudential Bank & Trust, for instance, sold its deposits to Wayzata-based TCF Financial Corp. earlier this year. Others have closed or repurposed their deposit operations.

Minneapolis-based Ameriprise Financial Inc. also is in the process of turning Ameriprise Bank from a federal savings bank to a non-depository trust, a process it expects to complete by the end of the year.

But turning bank units into credit unions is not the popular option.

There's no profit motive, noted Pat Keefe, spokesman for the Credit Union National Association. Keefe said his organization thinks the last time a U.S. bank converted to a credit union charter was 1996, when a bank serving Eastman Kodak employees converted to ESL Federal Credit Union in Rochester, N.Y.

David Royal, deputy general counsel for Thrivent Financial for Lutherans, said the bank could have taken other approaches, such as liquidating, but that didn't seem prudent. Plus, the credit union model fits well with Thrivent because of its common bond with the Lutheran community, he said.

"We thought it was important to continue offering depository services to Thrivent members," Royal said, describing the credit union as "sort of an elegant way of solving a problem."

Jennifer Bjorhus • 612-673-4683