A dedicated Bellport resident and the founder of Old Purchase Properties, Mark Petheram has been a cornerstone of the local real estate community for more than 45 years.
Referred to by Women’s Wear Daily as “the town’s go-to real estate broker,” Mark combines unmatched experience with an intuitive understanding of Bellport’s lifestyle, architecture, and quiet sophistication.
His career began organically—scouting locations for professional photo shoots—ultimately shaping a lifelong ability to recognize potential, understand design, and read a property’s true value.
Over the decades, Mark has advised a wide range of clients, including notable figures in the worlds of art, fashion, finance and entertainment, always with discretion, warmth, and a down-to-earth approach.
Mark’s expertise has played a defining role in Bellport’s real estate story. He represented both the buyers and sellers in the highest recorded sale in the history of Bellport Village, a milestone that reflects not only his negotiation skills but also the deep trust the community places in him.
Beyond real estate, Mark has spent years giving back to the village he calls home—serving as president and vice president of the Bellport Chamber of Commerce, contributing to multiple village boards, and supporting countless local fundraising initiatives. His civic commitment is not performative; it’s simply who he is.
Avidly connected to the Great South Bay as a lifelong boater, Mark brings an additional layer of insight to waterfront and coastal properties, guiding clients through the nuances of Bellport’s shoreline lifestyle with ease.
Whether buying or selling, those seeking thoughtful, informed guidance consistently turn to Mark Petheram—a trusted advisor whose integrity, local knowledge, and genuine care have made him Bellport’s most respected name in real estate.
