Arthur G. Cohen began a roller-coaster real estate career with a $25,000 investment in tract housing on Long Island before creating the nation’s largest publicly held real estate company, teaming up with tycoons like Aristotle Onassis to build trophy Manhattan skyscrapers. His reach extended well beyond New York City. Fortune called the company he took public in 1971, the Arlen Realty and Development Corporation, the largest publicly held real estate enterprise in the nation. It operated in 39 states and bought, sold, developed or managed a vast array of shopping centers, office buildings, apartment houses and a large planned community in Florida, Aventura. In its heyday, in 1975, it controlled over $1.7 billion ($7.5 billion in today’s dollars) of real estate assets. He also ventured beyond real estate. He owned parts of Braniff Airlines and the restaurant chains Houlihan’s and Darryl’s as a result of leveraged buyouts. Through Arlen Realty, he owned much of E. J. Korvette (also known as Korvette’s), the discount-store chain. He was unsuccessful in attempts to buy The New York Post and the Plaza Hotel, across from Central Park. Mr. Cohen had another major advantage: his father-in-law, Charles Bassine, who owned Spartan Industries, which owned Korvette’s. In 1971, Mr. Cohen and Mr. Bassine merged their companies to form Arlen and issued shares on the New York Stock Exchange to raise capital. He earned a degree in business from the University of Miami and a law degree from New York Law School, taking classes at night. His golf game was so good that he considered turning pro. In June 1954, he married Karen Bassine from Great Neck, on Long Island. She survives him, as do their daughters, Lauren Reddington, Susan Siegel, Debra Duran, Rochelle Rosenberg and Kathy Horowitz; his sister, Marilyn Davimos; and nine grandchildren.