Morton Olshan, whose commercial real estate career stretched more than six decades, has died at 99 years old, his family company announced.

In 1959, Olshan, who was known as Mort, founded what is known today as Olshan Properties, a company spokesperson said. Over his 66 years of ownership, the company grew to one of the largest privately owned, diversified real estate portfolios in the country.

“My father's journey from the son of poor immigrant parents in Brooklyn to becoming a national pioneer in real estate was truly the embodiment of the American dream,” his daughter, Olshan Properties Chairman and former CEO Andrea Olshan, told Bisnow in a statement.

The company today owns more than 9M SF of retail, 13,000 residential units, more than 1,000 hotel rooms and 3M SF of office space across 11 states.

Olshan was born in 1925 and died on Feb. 19. He is survived by his wife, Carole; children, Andrea and Michael; and five grandchildren, Commercial Observer reported.

During his time at the helm, Mort Olshan also led the rehabilitation of a 12,000-unit residential community spanning 171 buildings in the Bronx’s Parkchester neighborhood, one of his proudest achievements. Olshan became a principal owner of YankeeNets LLC in 2000 and served on the board of directors of the New York Yankees.

His conversion of 361 Fifth Ave., a luxury department store founded in 1895 and known as the B. Altman Building, into a nonprofit education and research facility earned him a Municipal Art Society award.

Olshan was also a board member of the New York Urban Coalition and the Community Preservation Corp., a trustee emeritus of the Horace Mann School and represented the New York City Comptroller’s Office on the board of trustees of the Metropolitan Museum of Art.

“He viewed real estate as not only an investment vehicle, but also, and more importantly, a means to be able to positively impact communities,” Andrea Olshan said. “The transformation of Parkchester and the innovative reimagining of the historic B. Altman building on Fifth Avenue exemplified his unwavering belief that success is defined by creating positive change in the world, not financial gain.”

Andrea worked alongside her father for 17 years, taking over from him as CEO before stepping down from the position in 2021 to become CEO at REIT Seritage Growth Properties.

Mort Olshan also served as a member of the President’s Council of the New York Public Library. The New York Landmarks Conservancy in 2021 named him a living landmark in recognition of his philanthropy.