Evansville-based Old National Bancorp (Nasdaq: ONB), the parent of Old National Bank, says it has entered into a definitive merger agreement with Chicago-based First Midwest Bancorp Inc.

The banking companies say the all-stock merger has a total market value of $6.5 billion. Together, the banks have $45 billion in total assets.

The new organization will operate under the Old National Bancorp and Old National Bank names, with dual headquarters in Evansville and Chicago.

Under the terms of the agreement, First Midwest stockholders will receive 1.1336 shares of Old National common stock for each share of First Midwest common stock they own.

Once the transaction is complete, the First Midwest stockholders are expected to represent about 44% of the new company.

“We are confident that the powerful synergies, additional market coverage and financial strength this partnership creates will drive long-term shareholder value, and we are excited about combining the outstanding legacies of two strong, client- and community-focused organizations,”  said Old National Chairman and Chief Executive Officer Jim Ryan, who will remain at CEO.

First Midwest Chairman and CEO Michael Scudder will serve as executive chairman.

The transaction is expected to close in late 2021 or early 2022.