Concord-based Barrett & Co. has rebranded itself, joining real estate franchise Sotheby’s International Realty.

Founded by Jane Barrett in 1977, the brokerage has been owned and operated by past Massachusetts Association of Realtors President Laurie Cadigan since 2007. Under the partnership with Sotheby’s, Cadigan retains full ownership of the brokerage but its properties will now be marketed under the Sotheby’s brand. The brokerage’s website and marketing materials have been completely redesigned.

Cadigan said she made the decision to join the franchise in order to increase her brokerage’s international exposure. "There’s not another brand I would consider," she said. "They’re the premier marketers in the luxury space in our market area. I think it’s going to provide a whole different level of service to our clients."

Sotheby’s International, a luxury market specialist, has 623 offices in 49 countries and territories. The Barrett acquisition increases their number of Massachusetts offices from 27 to 30.

The rebranding is already having an effect. "I’ve had an awful lot of phone calls from people who would consider joining us now," said Cadigan. And sellers "know now we have an incredible level of international service."