Gibson Sotheby’s International Realty has acquired Madden Group, a New Hampshire brokerage serving the Seacoast region and nearby markets, and opened an office in Portsmouth, New Hampshire.

The Portsmouth office is Gibson Sotheby’s first outside Massachusetts.

Jennifer Madden, former principal owner and managing broker of Madden Group, will join Gibson Sotheby’s as vice president for New Hampshire.

Madden Group serves also serves clients in Massachusetts and southern Maine. Its short-term vacation rental division, Rising Tide Rentals, will continue operating under its current name.

“Jenn has built a brokerage that reflects many of the values we’ve prioritized as we’ve grown: a boutique culture, close collaboration, and a deep commitment to the communities it serves,” said Larry Rideout, chairman and founder of Gibson Sotheby’s International Realty.

“This builds on a business already active in New Hampshire, where our agents have long served clients from Newburyport and across coastal New England, and Jenn’s team is an exceptional cultural fit.”

The acquisition expands Gibson Sotheby’s International Realty’s presence in northern New England as the company continues operations in coastal Massachusetts and nearby markets.

“In an industry that has experienced significant change in recent years, our continued growth reflects the stability of our company and the strength of the advisors who choose to build their businesses here,” said Colleen Barry, CEO of Gibson Sotheby’s International Realty.

“We’re excited to support Jenn and her team through the Sotheby’s International Realty network, connecting their clients to buyers and sellers around the world.”

Madden said the acquisition will allow her team to maintain its regional focus while gaining access to broader resources.

“Since 2010, we’ve built our business on trust, local expertise, and strong relationships across the Seacoast region,” she said. “Joining Gibson Sotheby’s International Realty allows us to pair that foundation with the support and global reach of the Sotheby’s International Realty brand, elevating what we can offer our clients while continuing to serve the communities we know best.”

Gibson Sotheby’s International Realty reported $4 billion in 2025 sales volume.

This article was generated using HousingWire Automation and reviewed by a HousingWire editor before publication. The system helps convert company announcements and industry data into HousingWire-style news coverage.