Chemical Financial Corporation, which operates Chemical Bank, is merging with TCF Financial Corporation - a deal that will create a $45 billion bank with more than 500 branches across nine states.

Under the terms of the "all-stock mergers of equals" deal, TCF Bank will merge into Chemical Bank - but the combined new company will operate under the TCF name and brand. The merger will create a "premier Midwest bank headquarted in Detroit," according to a press release, one that will "leverage the strengths of Chemical’s community banking and wealth management capabilities with TCF’s large deposit franchise and expertise in wholesale lending on a national basis."

The deal will focus on creating "significant" banking operation centers in Minneapolis, Midland, and Chicago. “With a shared strategic vision and increased scale and capabilities, our two complementary banking platforms will be positioned to better serve our customers and communities,” said Chemical’s Chairman Gary Torgow. “The combination of TCF and Chemical creates the largest midcap bank in the Midwest, poised to deliver double-digit EPS accretion for each set of shareholders, significant cost synergies, top-tier return metrics, a more diversified balance sheet and a lower risk profile. We also share a deep commitment to supporting and giving back to the communities we serve."

The deal, which is subject to regulatory approval, is expected to close later this year.