Caroline Kennedy will seek the Senate seat that Hillary Rodham Clinton is vacating to become secretary of state.

Kennedy called New York Gov. David Paterson yesterday to "express her interest in the job," Paterson spokesman Errol Cockfield said. Kennedy spokesman Stefan Friedman confirmed that she would seek the Senate seat.

Kennedy, 51, was six days shy of her sixth birthday when her father, President John F. Kennedy, was assassinated in Dallas. After avoiding politics for much of her adult life, she endorsed Barack Obama in January and campaigned for him around the country. She also spoke at the Democratic National Convention and helped select Joseph R. Biden Jr. as his running mate.

Obama has called her "one of my dearest friends."

Paterson has said he will not announce an appointment until Clinton is confirmed as secretary of state. Hearings will not begin until after Obama's Jan. 20 inauguration.

Many who have worked with Kennedy on projects give her high praise.

"My knowledge of her in the area of education and on behalf of children generally, the fact that she has written several books, and her other civic involvement, more than qualifies her to be senator," civil rights activist Al Sharpton said.

Kennedy's cousins Robert F. Kennedy Jr. and Kerry Kennedy have said recently that Caroline would be a good fit for the job, once held by her uncle Robert F. Kennedy.

"The governor is making up his mind, but there's no one like Caroline; she's unique," Kerry Kennedy said, noting her cousin's accomplishments as a best-selling author on civil liberties and as a fund-raiser for New York City schools.

Schools Chancellor Joel Klein, who recruited Kennedy to form the Education Department's Office of Strategic Initiatives, credited her with creating a philanthropic framework that has raised more than $400 million, including $51 million from the foundation headed by Microsoft Corp. founder Bill Gates.

"I think she'd be terrific," Klein said last week.