WARREN — Northwest Bank, a subsidiary of Northwest Bancshares Inc., has announced the completion of its acquisition of 18 full-service offices and one free-standing drive-thru facility in Western New York from First Niagara Bank, increasing Northwest’s New York regional presence to 37 offices.

The acquisition became official on Friday.

Officials said Northwest has converted the acquired offices and transitioned all customer accounts. Those locations opened as Northwest Bank offices on Monday morning, with 180 new team members servicing 80,000 new customers with deposits of approximately $1.6 billion.

As a result of the acquisition, Northwest Bank now has 176 locations throughout Pennsylvania, New York, Ohio and Maryland, including across the Bradford area.

“We are pleased to have successfully completed the most significant acquisition in the 120 year history of our company,” said William J Wagner, Northwest’s chief executive officer. “We extend a warm welcome to our new customers as well as the employees of these offices who will continue to serve them. This acquisition is a tremendous opportunity for Northwest to expand its presence in Western New York, and we remain firmly committed to playing a larger role in the future success of the region.”

Customers with questions about the transition of their accounts are encouraged to stop by any Northwest office during business hours; call Northwest’s Customer Service at 1-877-672-5678; or visit the website www.northwest.com.

Boenning & Scattergood served as financial advisor and Luse Gorman, PC served as legal counsel to Northwest in the transaction.