(Recasts with confirmation, reaction)
By Edith Honan
NEW YORK, Feb 27 (Reuters) - After 35 years on the job, Manhattan District Attorney Robert Morgenthau said on Friday he will not seek re-election to a position in which he has focused in recent years on prosecuting serious financial crimes.
Morgenthau, 89, has served as Manhattan district attorney longer than anyone else in history, outlasting countless actors who played the role of the D.A. in film and television dramas.
He said he will continue serving another 10 months until his current term ends.
"Some people are slow learners and it took me a long time to realize that I was getting older," Morgenthau said at a news conference announcing his decision.
He has been a fixture in the New York Democratic Party for decades. His father served as U.S. treasury secretary and his grandfather was ambassador to the Ottoman Empire.
Mayor Michael Bloomberg described him as "a New York Institution," saying, "few people have served the city longer or more ably." Police Commissioner Raymond Kelly said: "He's just an icon, he's a legend."
But Columbia Law School Professor Daniel Richman called Morgenthau's tenure a "mixed bag" whose work on white collar cases was often done "on the fly" and with an unclear agenda.
As chief prosecutor for state crimes in the New York City borough, he has focused on white collar crime and Wall Street misdeeds in recent years as violent crime fell in Manhattan.
Morgenthau's decision was first reported by the New York Post, which cited "several sources" saying that he had begun privately calling top deputies into his office to inform them.
He has long kept the press and politicians guessing about his future. When asked about it in a 2007 interview with Reuters, he said, "Skip retirement. That's precocious."
Voters in the Democratic, Republican and smaller parties will choose their candidates for district attorney in September with the winners of the primaries competing for the post in November.
Before making his first of eight runs for district attorney in 1974, Morgenthau served as U.S. Attorney in Manhattan, having been appointed by John F. Kennedy and fired by Richard Nixon.
His father was longtime Treasury Secretary Henry Morgenthau, Jr., who was appointed by Franklin Roosevelt during the Great Depression in 1934. His grandfather Henry Morgenthau, Sr. was Ambassador to the Ottoman Empire during World War One.
At least two people have expressed desire for the job.
Leslie Crocker Snyder, a former judge who lost to Morgenthau in the Democratic primary four years ago, has said she will run again for the post.
Cyrus Vance Jr., the son of a former U.S. secretary of state, filed papers to launch a "Cyrus Vance for District Attorney" committee a year ago.
The Post named Morgenthau's longtime deputy Dan Castleman as another possible candidate.
Morgenthau's office won conviction of former Tyco International Ltd. Chief Executive Dennis Kozlowski, who was sentenced to 25 years for looting the conglomerate, and investigated the Bank of Credit and Commerce International (BCCI) fraud scandal.
BCCI, a Middle East-backed bank, was shut down by regulators around the world in July 1991. (Reporting by Daniel Trotta and Edith Honan; Writing by Daniel Trotta; Editing by Eric Walsh)