Jay Kriegel, a prominent figure in New York City's political, legal and business spheres who co-founded The American Lawyer, died Thursday at age 79.

Kriegel died at his weekend home in South Kent, Connecticut, from complications of melanoma, according to Kathleen Anne Corless of the Related Cos., a real estate development firm where Kriegel worked.

Kriegel, a native of Brooklyn, got his start fresh out of Harvard Law School on John Lindsay's mayoral campaign, The New York Times reported. The liberal Republican congressman from Manhattan won the 1965 election and named Kriegel his chief of staff. Steven Brill, who in 1979 co-founded The American Lawyer with Kriegel, was then a student at Yale Law School and a mayoral assistant.

News articles from the era focus on Kriegel's work as the mayor's envoy to the New York Police Department, which was roiled by allegations of corruption leveled by officer Frank Serpico and others around 1970. Lindsay created the Knapp Commission to investigate the problem, and Kriegel came under scrutiny when he appeared to contradict himself in testimony over what he told Lindsay of his own contacts with Serpico and another whistleblower, according to a 1972 article in the Times.

Brill and Kriegel founded The American Lawyer in 1979. Kriegel left in 1982 in what Brill later described as a "divorce" stemming from different visions for how the magazine should be run, according to The Washington Post.

After departing the publisher's seat, Kriegel helped New York politicians rally to save the state and local tax deduction, the Times reported in an obituary. Later in the decade, he became a senior executive at CBS, whose chairman Laurence Tisch he had known since the 1970s.

According to an obituary published by his family, Kriegel worked for the communications firm Abernathy MacGregor and advised the leaders of Kazakhstan and Turkey. In the early 2000s, Kriegel helmed an unsuccessful effort to try to bring the 2012 Olympics to New York. More recently, he worked at the Related Cos., the real estate developer that built Hudson Yards.

"The energy Jay brought to his work made him a cherished personal and professional friend, mentor and leader," said Stephen Ross, Related's chairman, in a statement. "For nearly 40 years, he worked tirelessly with officials in the city of New York, Washington, D.C., and the business community to help build a better city for all New Yorkers. We share this tremendous loss with the city that Jay loved and championed over the years."

Efforts to reach Brill and Kriegel's family Friday were not immediately successful.