The September 11 attacks were initially slated to be carried out in May or June of 2001 but were postponed by Al Qaeda leaders as lead hijacker Mohammed Atta was not ready, said a Washington Post report published on Tuesday.
The report was based on 'sources privy' to the independent commission probing the attacks allegedly masterminded by the Osama bin Laden-led Al Qaeda.
The commission, said the report, has based its conclusion on new evidence collected from interrogating prisoners at Guantanamo Bay and other centres.
The report said that Khalid Sheik Mohammed, mastermind of the attacks, persuaded bin Laden to postpone the attacks by several months because of organisational problems.
The commission report, if it actually makes such a conclusion, is in direct contrast with the theories of the Federal Bureau of Investigation that suggest the attacks were planned much later.
The draft of the report, said Washington Post sources, have been circulated among government and commission officials in recent days.
The panel will release its final report in late July. It is also expected to release a separate report on whether US fighter jets would have been able to intercept the American Airlines Boeing before it crashed into the Pentagon.