Montana's largest bank is selling off a portion of it's company. First Interstate Bank announced Tuesday the sale of its subsidiary I-Tech Corporation, a Billings based regional data-processing company.

I-Tech provides information and item-processing services to more than 150 financial institutions.

I-Tech is being sold to Fiserv, a fortune 500 company based in Wisconsin, for $40-million.

According to a joint press release, many banks are divesting their data processing operations.

First Interstate and Fiserv have had a business relationship for three decades and a good fit for a buyout.

Some of the 150 I-Tech employees will be transferred back to First Interstate Bank, and the rest will continue with I-Tech under new ownership.

Fiserv is headquartered in suburban Milwaukee.