Great-West Lifeco’s U.S. subsidiary plans to buy a stake in a Montana-based third-party administrator of employee health plans.

It will acquire an 80% interest in Benefit Management Corp, whose principal subsidiary is Allegiance Benefit Plan Management.

Allegiance is the leading medical administrator for large employer groups in Montana and has the second largest overall market share among health plans in the state.

The transaction will add nearly 90,000 medical members to Lifeco’s Great-West Healthcare division. The deal is expected to close in the second quarter of this year.

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