Jan. 25 (Bloomberg) -- Robert F. Kennedy Jr., the environmentalist son of slain U.S. Senator Robert Kennedy, said he won't run for New York Attorney General next year because he wants to spend more time with his family.

Kennedy, the lead prosecutor for environmental advocacy group Riverkeeper, is the father of six children, the youngest of whom is 3 years old. While Kennedy, 51, said in a statement today that he plans to run for political office in the future, now isn't the right time.

``It has become increasingly clear that a run for public office -- where I can bring greater effect to the issues for which I care deeply -- will indeed be the next step in my career,'' Kennedy said in the statement. ``However, after careful consideration and discussion with my family, I have decided that I cannot take this step at this time.''

As the son of a former senator from New York and the nephew of John F. Kennedy, the U.S.'s 35th president, Robert Kennedy Jr. would have brought a familiar name to the race for attorney general. The Democratic primary likely would have pitted Kennedy against his brother-in-law, fellow scion of a political family, Andrew M. Cuomo.

Kennedy delayed his decision, in part to weigh the consequences of running against Cuomo, who is divorcing Kennedy's sister, Kerry.

Cuomo, 47, who served as secretary of Housing and Urban Development under former President Bill Clinton, hasn't decided whether he will run. In 2002, Cuomo lost a bid to become New York's governor, an office held by his father, Mario Cuomo, from 1983 to 1995.

Spitzer Successor

Had he run, Kennedy would have vied to succeed current Attorney General Eliot Spitzer, who will run for governor of New York in 2006. Spitzer gained national prominence for his office's investigations of Wall Street analysts, mutual fund managers and the insurance industry.

Kennedy, who is a graduate of Harvard University and the University of Virginia's law school, joined Riverkeeper in 1984. As lead prosecutor, he is responsible for suing alleged polluters of New York's Hudson River.

Kennedy's father was assassinated in April 1968 while campaigning for the presidency. His uncle, John F. Kennedy, was killed Nov. 22, 1963, in Dallas. Their brother, Edward Kennedy, has represented Massachusetts in the U.S. Senate since 1962.

To contact the reporter on this story: Jesse Westbrook in Washington at jwestbrook1@bloomberg.net.

Last Updated: January 25, 2005 11:19 EST