S&T Bancorp Inc., a U.S.-based bank holding company, has agreed to purchase peer DNB Financial Corp., the holding company for DNB First.

Under the $206 million all-stock deal, DNB shareholders will receive 1.22 shares of S&T stock for each share of DNB stock.

S&T expects the acquisition of DNB Financial to increase its assets from $7.3 billion to $8.4 billion, branch network by about 25 percent and also be accretive to earnings per share in 2020.

Furthermore, the transaction, which has been unanimously approved by the boards of directors of both companies, is expected to close in the fourth quarter, pending more approvals.