Greylock Federal Credit Union has selected John Bissell as its new president and chief executive officer.

Bissell will replace retiring CEO Marilyn Sperling on Oct. 1. Sperling will remain involved with Greylock to help complete the merger with Berkshire Federal Credit Union.

Bissell joined Greylock in 2003 as vice president of marketing and human resources. He was promoted to senior vice president in 2007 and was named executive vice president in 2010.

Bissell’s volunteer roles have included serving on the Colonial Theatre Board, chairing the Berkshire United Way board of directors, and founding Pittsfield Promise, an early literacy initiative.

“John is well-recognized as a passionate and effective leader in the community,” Chair Jerry Burke said in a statement. “He understands Greylock’s unique connection to Berkshire County, and how important it is for us to make business decisions with an eye to the greater good.”

“I am honored and humbled to be chosen as Greylock’s CEO,” Bissell said. “Marilyn has been a great leader and I know I have some big shoes to fill. More than 70,000 people have entrusted us with $1 billion of their financial assets, which makes Greylock a significant part of Berkshire County’s economic engine. … I believe we have the strongest financial services team in the region, and it is my privilege to lead this team forward to meet the challenges and opportunities that lie ahead.”