Bremer Financial and Old National Bank are joining forces and will create the third-largest bank in the Twin Cities, the companies announced Monday.

Old National is acquiring Bremer in a deal worth $1.4 billion. Bremer Financial is the company that operates Bremer Bank.

When the merger is complete, the new corporation will have more than $70 billion in assets and expand Old National's footprint with 70 more banking centers throughout Minnesota, North Dakota and Wisconsin.

"This partnership represents an outstanding fit between two highly compatible, relationship- and community-focused banks," said Old National Chair and CEO Jim Ryan in a statement Monday. "When you look at what has made Bremer Bank a leading institution since 1943, what you quickly find are the same strategic priorities and cultural principles that have guided Old National's success for 190 years: a strong deposit franchise, a diversified loan portfolio accentuated by exceptional credit quality, and a passion for investing in and strengthening communities. I am incredibly confident that, through this partnership, Bremer and Old National will be even better together."

As of September, Bremer had $16.2 billion in assets, $11.5 billion in total loans and $13.2 billion in deposits.

The news comes months after Bremer, one of Minnesota's largest banks, which is owned by the Otto Bremer Trust, came to a legal settlement. The trust wanted to sell the bank, saying it would be more profitable while Bremer Financial looked to merge with Great Western Bancshares.

The two sides reached an agreement in July paving the way for Monday's announcement.

"For more than 80 years, we've been honored to carry out the legacy of our founder Otto Bremer," said Jeanne Crain, president and CEO of Bremer. "When our majority shareholder, the Otto Bremer Trust, reaffirmed its interest in selling Bremer Bank, we appreciated the opportunity to identify a partner through a collaborative process to ensure the best possible outcome for our customers, employees, and our communities. With Old National, we have confidence we found a great fit."

The sale is subject to regulatory approval and customary closing conditions.