Washington, Dec 30 : The Central Intelligence Agency chief, General David Petraeus had decided to resign over US President Barack Obama''s decision to reduce troops in Afghanistan, a new biography has suggested.

But he decided against quitting because he thought it would be a "selfish, grandstanding move with huge political ramifications".

Obama had earlier announced to withdraw 33,000 US troops from Afghanistan by September 2012 after Petraeus took over the post in April.

The CIA has, however, rejected the biography's claims.

"Director Petraeus has publicly stated that he never contemplated resignation," The BBC quoted CIA spokeswoman Jennifer Youngblood, as saying.

The biography titled `The Education of General David Petraeus' details General Petraeus''s 37-year career, from West Point cadet to masterminding the counter- insurgency in Iraq and Afghanistan.

The biography also reveals that General Petraeus was angered over being perceived as outsider in the current US administration.

The book will be released next month. (ANI)