Arthur Zankel (search), the financier who gave $10 million for the Carnegie Hall recital space that bears his name, plunged to his death from his ninth floor apartment in an apparent suicide, police said Friday. He was 73.

Zankel, Carnegie Hall's (search) vice chairman, died Thursday at New York Hospital after apparently jumping from his Fifth Avenue apartment, Detective Noel Waters said, confirming a report in The New York Sun. Waters said Zankel jumped around 11 a.m. Thursday and landed in a rear courtyard.

Zankel, a member of the Citigroup Inc. (search) board of directors from 1986 until last year, specialized in real estate investment through his firm High Rise Capital Management. He served as a co-managing partner of First Manhattan Co. for almost 20 years, until 1997.

His donation helped fund the $100 million venue at Carnegie Hall that opened in 2003. Zankel Hall fulfilled Andrew Carnegie's original vision for three performance spaces at the complex, offering an intimate venue — with seats for about 600 compared with 2,804 in the main Isaac Stern auditorium.

Citigroup Chairman Sanford Weill said Zankel (pronounced zan kell') was an astute adviser — and his best friend.

"He was the director that really understood the numbers, would quickly be able to dissect the details of a transaction and could catch things that didn't make a heck of a lot of sense," Weill said in Friday's editions of the Sun.

Zankel loved that the venue that carried his name brought together musicians from all over the world, said Weill, who is the namesake for Carnegie Hall's third venue, the 268-seat Joan and Sanford I. Weill Recital Hall.

The construction of Zankel Hall required the digging of more than 6,300 cubic yards of bedrock — enough to fill 1 1/2 Olympic-size swimming pools. The hall sits about 40 feet below street level, directly under the main auditorium. A remote-control system of lifts, steel trusses and wagons allow artists to rearrange the floor and stage to fit most any performance.

"Arthur Zankel will be remembered as a kind, caring, humorous, brilliant, and wise person," Kenneth Bialkin, who served on the board of directors of Citigroup along with Zankel, told the Sun.

The financier also was a trustee of the Teachers College at Columbia University and a director of White Mountains Insurance Group Ltd.

Survivors include his wife, Judy, and four sons from a previous marriage.