* G8 to warn it is too early to withdraw stimulus

* US official: no talk in White House of second stimulus

* Wall Street closes flat, European shares down

* OPEC says may take years for oil demand to recover

* Alcoa kicks off U.S. earnings reporting season

(For more on the financial crisis, click on [nCRISIS])

By Jackie Frank

WASHINGTON, July 8 (Reuters) - The fragile recovery from the worst global recession since World War Two will slowly pick up pace into next year, the International Monetary Fund said on Wednesday, but world leaders agreed stimulus spending must remain in place until the economic turnaround is secure.

Fears that high unemployment and slow consumer spending could strangle the nascent recovery pushed Wall Street lower for much of the day before U.S. stocks ended little changed. [ID:nN08409947]