S&T Bancorp Inc. has agreed to acquire DNB Financial Corp., the holding company for community bank DNB First, in an all-stock transaction valued at approximately $206 million. The merger will expand S&T Bank’s footprint into Southeastern Pennsylvania.

On a combined basis, S&T will have approximately $8.4 billion in total assets.

The terms of the merger agreement have been unanimously approved by the boards of both companies. S&T and DNB expect to complete the transaction during the fourth quarter of 2019 after satisfying the customary closing conditions, including regulatory approvals and the approval of DNB shareholders.

“Merging with such a venerable institution located in a growing Southeastern Pennsylvania market dovetails nicely with our expansion into the Central Pennsylvania market in 2015, and our overall strategic growth strategy focused on Pennsylvania, Ohio and New York,” S&T CEO Todd D. Brice said in a statement. "Alongside DNB’s seasoned staff, we look forward to building on the bank’s legacy as well as working with existing and future clients."

DNB shareholders will receive 1.22 shares of S&T stock for each share of DNB stock. S&T expects the merger to be accretive to earnings per share in 2020.

DNB First is headquartered in Downingtown, Pennsylvania, with 14 locations. S&T operates in five markets: Western Pennsylvania, Central Pennsylvania, Northeast Ohio, Central Ohio and Upstate New York.