A former HarborOne Bank executive will take the helm of Marlborough’s St. Mary Credit Union, making her the third CEO the firm has had this year.
Brenda Diepold will take over as president and CEO of the credit union on Oct. 5, replacing Jim Petkewich, who will retire in February, according to an announcement from SMCU on Tuesday.
Diepold has 32 years of banking experience, coming to SMCU from Brockton-based HarborOne Bank, where she most recently served as executive vice president, chief banking officer. HarborOne was acquired by Boston-based Eastern Bank in late 2025.
Prior to HarborOne, Diepold worked at firms that include Century Bank, Santander Bank, Fleet Bank and Sovereign Bank. She graduated from the University of Rhode Island and is a resident of Dedham.
“I truly believe having the opportunity to work for an organization that’s focused on relationships and growth that delivers back value to its members is extremely important, and I’m thrilled to be able to be a part of that type of structure,” Diepold told WBJ. “When you look at a credit union, especially SMCU, they are built to invest in their people and capabilities to really help families and businesses in the communities they serve, and that matters a great deal to me.”
Petkewich took on the roles of president and CEO in May after the departure of Grace Lee. Having come to SMCU from M&T Bank, Lee returned to the Buffalo-headquartered bank in July after having spent less than a year leading SMCU.
“Jim’s leadership and deep knowledge of this organization was critical to successfully completing our merger with MetroWest this past summer,” Brian Bouvier, board chair of SMCU, said in the announcement. “As we looked towards SMCU’s future, our priority was finding a proven leader to provide long-term stability and guide St. Mary’s Credit Union through its next chapter of growth. We found that leader in Brenda.”
The credit union said in its announcement Petkewich had previously planned to retire, changing course after Lee’s departure, which he labeled a surprise.
Petkewich will remain at SMCU as a special adviser to the CEO and board as the credit union completes its integration with Framingham’s MetroWest Community Federal Credit Union. SMCU merged with MetroWest in July, creating an entity with about $1.15 billion in assets and 60,000 members.
“I am thrilled to be able to partner with Jim as we go through this transition,” Diepold said. “He will be assisting in that process. The team, the board, and Jim have great longevity and stability, and I’m going to capitalize on that as I build lasting relationships with them. But stability is more than just a CEO; it’s a strong team with a clear strategy.”
SMCU is the fourth-largest credit union in Central Massachusetts, with $1.04 billion in assets as of March 2026, according to information provided to the WBJ Research Department.
Eric Casey is the managing editor at Worcester Business Journal, and primarily covers the real estate and banking & finance industries.
