UPDATED 2:50 p.m. Pacific on 4/25/18 to include additional comments from First Interstate Bank CEO Kevin Riley. 

UPDATED 11:35 a.m. Pacific on 4/25/18 to add Chad Burchard's role as market president. 

Billings, Mont.-based First Interstate BancSystem Inc. has agreed to acquire Spokane-based Northwest Bancorporation Inc., parent company of Inland Northwest Bank, the companies announced this morning.

First Interstate intends to continue operating all 20 of INB's banking offices and expects the transaction to be completed late in the third quarter or early in the fourth quarter of this year.

Russell Lee, president and CEO of INB, says in a written statement, "INB's growth and momentum spurred First Interstate's interest in us, and consequently, a tremendous opportunity for our combined company to expand our presence throughout the Pacific Northwest."

Lee also says, "We're confident that, together, we will deliver a high standard of excellence, continue to value our relationships in each of our communities, and generate strong returns for our shareholders, many of whom have supported INB since it was founded almost 30 years ago," Lee says.

The all-stock acquisition is valued at $160.9 million, or $21.03 a share, the announcement says.

INB says it currently has $827 million in assets, $669 million in loans, $721 million in deposits and $82 million in shareholders' equity.

Jason Miller, INB's senior vice president of marketing and culture, says First Interstate Bank "will adopt all naming rights" of facilities and programs currently associated with INB, particularly the 140,000-square-foot INB Performing Arts Center in downtown Spokane.

"First Interstate had officials in town last week and got a chance to look around," Miller says. "They're really excited about the future relationship with the performing arts center."

INB Chief Banking Officer Chad Burchard will serve as the market president for First Interstate once the acquisition is completed, Miller says. In that role, he says, Burchard will oversee the bank's operations in the Spokane area, North Idaho, the Palouse region, and the Columbia Basin.

Beyond that, Miller says, it remains to be seen about what the future holds for senior leadership members at INB.

"At this point, that hasn't been communicated to us," he says.

First Interstate President and CEO Kevin Riley says, "First Interstate Bank and INB will work closely to ensure the merger has as little impact on employees as possible. Our expectation is that the majority of INB employees will have the opportunity to continue as part of the new First Interstate Bank team."

After finalizing the purchase, First Interstate will have approximately $13.1 billion in total assets, $8.3 billion in total loans, $10.7 billion in total deposits, $1.5 billion in shareholders' equity, and 146 banking offices.

First Interstate offers banking services throughout Montana, Washington, Idaho, Oregon, Wyoming, and South Dakota.

"Our partnership with INB supplements and accelerates our expansion into the Pacific Northwest," says Riley.

Since expanding into Washington, Idaho, and Oregon last year, Riley says, "We have a tremendous respect and enthusiasm for these communities and markets. We're eager to deepen our presence and build relationships with the clients who call these beautiful regions home."

In pursuance of the merger agreement, Northwest shareholders will receive 0.516 shares of First Interstate Class A common stock in exchange for each share of Northwest common stock they hold, the press release says.

The exchange ratio is fixed and the shares received by INB shareholders are anticipated to qualify as a tax-free exchange. INB shareholders will own approximately 6 percent of First Interstate once the transaction is complete, the release says.

Northwest Bancorporation Inc. is one of nine publicly traded companies currently based here. By year's end, that number may be reduced to seven as Avista Corp. last year announced it would be acquired by Hydro One, a Canadian utility based in Ontario.

The potential loss of Avista and INB as publicly traded companies would mean the loss of nine publicly traded companies headquarters in the Inland Northwest since 2014.