The statement ended a night of confusion over whether she was in or out. Various media outlets reported Wednesday night that Kennedy had called Gov. David Paterson to pull out of the running for the seat to replace Hillary Clinton.
Then just before 11:00 p.m., The Associated Press reported a person close to Caroline Kennedy's decision said she had renewed her determination to win the appointment to the U.S. Senate seat once held by her slain uncle, Sen. Bobby Kennedy.
The hours of mixed signals were the latest twist in the Kennedy effort, which began with popular support that withered after she drew criticism in her brief tour and early press interviews.
Edward Kennedy, who has been treated for an aggressive brain tumor, suffered a seizure Tuesday at the inauguration of President Barack Obama.
The New York Post was first to report his niece's withdrawal from the Senate contest.
The New York Times cited a source it didn't identify as saying Kennedy withdrew out of concern for her uncle and his illness. But the Post cited an unidentified source as saying she dropped out because she learned Paterson had decided not to choose her.
Paterson said that on Wednesday he would begin reviewing the candidates' responses to the 28-page questionnaires he had asked applicants to complete. The forms asked about personal finances and other background issues, many of which Kennedy has long shielded from the public.
Kennedy, an author, lawyer and fundraiser for New York City schools, has long guarded her privacy, and the questionnaires were expected to include some closely guarded Kennedy financial data.
With Kennedy out of the mix, several candidates are under consideration, including Attorney General Andrew Cuomo, who surpassed Kennedy in statewide polls last week.
Paterson said Cuomo had outstanding credentials for the job. Cuomo was the housing secretary under President Bill Clinton. Cuomo was elected attorney general in 2006 and has since led national reforms in the student loan industry and had a role in reining in corporate spending on Wall Street.
Cuomo is also the most popular elected politician in New York in polls - higher than Paterson, whose approval rating, while still high, has been slipping.
Other contenders include Reps. Carolyn Maloney, of New York City, and Steve Israel, of Long Island, along with a strong upstate candidate, Rep. Kirsten Gillibrand, whose district runs along the Hudson Valley. Other hopefuls among the 10 or 20 Paterson said were under consideration include Reps. Jerrold Nadler and Brian Higgins and Buffalo Mayor Byron Brown.