The former first lady and one-time political rival to President Barack Obama quickly became one of the most influential members of his cabinet after she began her tenure at State in early 2009.
She has said publicly she did not plan to stay on at the State Department for more than four years.
Associates in the USA say Mrs Clinton has expressed interest in having the World Bank job should the Bank's current president, Robert Zoellick, leave at the end of his term, in the middle of 2012.
"Hillary Clinton wants the job," said one source who knows the secretary well.
A third source said Mr Obama has already expressed support for the change in her role.
It is unclear whether Obama has formally agreed to nominate her for the post, which would require approval by the 187 member countries of the World Bank.
The White House declined to comment.