Felix Rohatyn, a towering figure on Wall Street credited with saving New York from insolvency and who later served as US ambassador to France, has died at age 91.

He died at his home in Manhattan of unspecified causes, his son Nicolas confirmed to The New York Times.

Rohatyn was born in 1928 into a well-to-do Jewish family in Vienna -- his grandfather was a banker -- but the family was forced to flee to France amid the rise of the Nazis.

After German troops entered that country, he and his mother -- his parents had since divorced -- left on a circuitous journey to the US in 1942.

Rohatyn quickly learned English -- at one point he even tutored a young Edith Piaf while the singer was working in New York, the Times reported -- and then plunged into the world of finance, making a mark as a skilled deal-maker and sought-after merger specialist.

Mentored by Andre Meyer, the French financier who controlled the powerful Lazard Brothers investment bank (now Lazard), he did so well that Meyer would eventually say the student had surpassed the teacher. Rohatyn was made a partner in 1960.

He became a valued confidant and adviser of political and business leaders, earning a reputation as someone who could find an acceptable solution to any problem -- hence his nickname, "Felix the Fixer."

In the 1970s, when New York City was teetering on the brink of bankruptcy, crushed under its debt, city fathers turned to Rohatyn.

Felix Rohatyn (L), then the US ambassador to France, is seen meeting then-mayor of Bordeaux, Alain Juppe, on March 13, 2000
Felix Rohatyn (L), then the US ambassador to France, is seen meeting then-mayor of Bordeaux, Alain Juppe, on March 13, 2000 AFP / DERRICK CEYRAC

The job of restoring the metropolis to financial health proved more daunting than expected -- Rohatyn stayed with the task for years, even after the city finally balanced its budget in 1980.

"As a child, he fled Nazi oppression," Mayor Bill de Blasio posted on Facebook. "As an adult, he led the restoration of the city he came to call home. Felix Rohatyn's extraordinary life was a true New York City story."

After supporting the independent presidential candidacy of billionaire H. Ross Perot in 1992, Rohatyn -- a major donor to the Democratic Party -- was unable to persuade eventual winner Bill Clinton to name him Treasury secretary.

Instead he won a consolation prize: in 1997, Clinton named him ambassador to France, where he succeeded the popular Pamela Harriman.

Friends said Rohatyn was uniquely suited for the job. He knew the country well, spoke French fluently and was friends with Francois Mitterrand. The French government had honored him with its prestigious Legion of Honor award in 1983.

Rohatyn remained in that job for three years.

In his later years, he wrote a memoir, advocated for greater attention to the nation's aging infrastructure, and embraced philanthropic causes.