Former US Federal Reserve Chairman Alan Greenspan, in a memoir to be released on Monday, says the prime motive for the March 2003 US-led invasion of Iraq was oil, The Sunday Times reported.

In his long-awaited memoir, Greenspan will also deliver a stinging critique of US President George W. Bush's economic policies, according to the paper.

However, it is Greenspan's view on the motive for the 2003 Iraq war that is likely to provoke the most controversy, the paper said.

"I am saddened that it is politically inconvenient to acknowledge what everyone knows: the Iraq war is largely about oil," Greenspan says in the book, as cited by the paper.

Greenspan is understood to believe that Saddam Hussein, the former Iraqi president, posed a threat to the security of oil supplies in the Middle East, the paper said.

America and Britain have always insisted that the war had nothing to do with oil, and Bush said the aim was to disarm Iraq of weapons of mass destruction and end Saddam's support for terrorism, the paper pointed out.

Greenspan, 81, was the head of the US Federal Reserve from 1987 to 2006.

(Xinhua News Agency September 17, 2007)