Construction of a new bank on William Clarke Drive is officially under way.

Saco & Biddeford Savings Institution held a groundbreaking ceremony Tuesday for the sixth branch of Maine’s oldest bank. On Monday, the City Council gave final approval for the bank to have a freestanding sign on the site, which it shares with Hannaford.

The 3,900-square-foot building is scheduled to open for business in December. Employees at the new branch will include a manager, assistant manager, customer service representative, loan officer and tellers. Based in Saco, the 181-year-old bank has branches in Biddeford, Old Orchard Beach, Scarborough and South Portland.

“We’re thrilled to be coming here,” said Kevin Savage, the bank’s president and chief executive officer. “Westbrook is entering into a new phase of revitalization, but it also reflects a rich history that is not unlike our own.”