Wellesley Bank plans to open a new branch at 1 Federal St. in Boston’s Financial District, the company’s first foray into the largest central business district in the region.

The bank, which currently has three branch offices in Wellesley, will occupy 3,000 square feet of the 38-story office tower’s vacant ground floor retail space. The branch is scheduled to open in the fourth quarter of 2013.

"Opening an office in Boston has long been a key component of our company’s strategic plan for growth," Thomas Fontaine, the president and CEO, said in a statement. "We have been actively looking during the past year to establish a presence in Boston as a means to more effectively serve our clients and further increase the significant growth we’ve experienced as people leave large financial institutions and seek stable, more personalized banking and wealth management services at companies such as ours for their financial needs."

Last November, Tishman landed Iron Mountain as a 129,000-square-foot tenant for 11 years at the property after the building underwent a major renovation in 2011. The landlord has owned the tower since acquiring it from Jamestown for $514 million in 2006.