Gray, Gray & Gray LLP of Westwood, Mass., has merged in O’Toole & Company of Boston, effective Jan. 1.

Joe Ciccarello

Both firms serve closely held businesses and provide accounting, audit, tax strategy, estate planning, and business advisory services. The combined firm will operate under Gray, Gray & Gray’s name and will maintain offices in both Boston and Westwood. Financial terms were not disclosed.

As part of the deal, O’Toole & Company partners Timothy O’Toole and Karen Timmermans will become partners in the combined firm, raising the number of partners at Gray to 16. All of the staff members are expected to be retained, with a total staff count of 90 people.

“This is an important step for our new clients and allows us to offer them an even broader scope of services,” said Gray, Gray & Gray managing partner Joe Ciccarello in a statement. “The experience and skills of our two firms complement each other and, together, make us a stronger and more competitive organization.”

Gray, Gray & Gray was founded in Boston in 1945, and relocated to Westwood in 1999. O’Toole & Company was founded in Boston in 1979 by Timothy O’Toole.

“By combining the resources of two excellent accounting firms, we can better meet the needs of our clients as they grow and expand,” said O’Toole. “We are large enough to deliver any accounting, tax or wealth management service a client may need, while still remaining small enough to provide one-on-one attention.”