Gov. David Paterson’s pick for the senator seat left vacant by Secretary of State Hillary Rodham Clinton is Democratic U.S. Representative Kirsten Gillibrand, according to a source close to the governor.

Mrs. Gillibrand, a second-term lawmaker from upstate New York, has already accepted the appointment, one of her aids confirmed. The move will be publicly announced today at noon (1700 GMT) in Albany. The Democrats currently hold a 57-41 majority in the U.S. Senate. The 43-year-old congresswoman was considered one of the top contenders for the post along with Caroline Kennedy and state Attorney General Andrew Cuomo.

Yesterday, Kennedy unexpectedly withdrew from consideration. The 51-year-old daughter of late U.S. President John F. Kennedy reportedly called Gov. Paterson yesterday and told him she was having second thoughts about filling the Senate seat. 

Gillibrand will fill the post until 2010 when the term expires and a special election will fill the final two years of Clinton's term. The former first lady resigned from her seat in the Senate after she accepted the post of Secretary of State in President Barack Obama’s foreign policy team.

Gillibrand was elected to Congress in 2006 after defeating a long-term Republican incumbent and managed to get re-elected in 2007 by a wide margin. She is quite controversial among the liberal leaders of the Democratic Party for her conservative ideas on gun ownership rights and for the fact that she is backed by the National Rifle Association.

Mrs. Gillibrand also worked in the Housing and Urban Development Department during the Clinton administration. She managed to defeat Republican John Sweeney in the 2006 vote to represent New York's 20th District.