Indiana, Pa.-based S&T Bancorp, Inc. said shareholders of IBT Bancorp Inc., owner of Irwin Bank, approved the merger of the two companies yesterday.

Each share of IBT Bancorp common stock outstanding immediately prior to the merger will be converted into cash or shares of S&T Bancorp common stock with cash in lieu of fractional shares.

S&T Bancorp said it has received all necessary regulatory approvals for completion of the merger, which is expected to be effective in early June.

With this merger, S&T Bank will have combined assets of more than $4.3 billion and 55 branch offices. Irwin Bank is a wholly owned subsidiary of IBT Bancorp.