Southwest Bancorp Inc. shareholders on Oct. 17 voted in favor of the Stillwater, Okla.-based company's acquisition by Pine Bluff, Ark.-based Simmons First National Corp.

The Simmons First-Southwest merger was valued at approximately $564.4 million when it was announced in December 2016. Simmons First also has a pending acquisition for First Texas BHC Inc. Both deals have received Federal Reserve approval and are expected to close within the year.