GENEVA, Sept. 8 (Reuters) – United Nations economists said on Monday there would be no early recovery from global recession and warned that any move to ease back quickly on government stimulus programs could make the crisis worse.

In its annual report, the UN trade and development agency UNCTAD also urged the creation of a new world reserve system using several currencies rather than just the US dollar, and called for tough controls on cross-border financial flows.

But in Milan, Italy' IMF Managing Director Dominique Strauss-Kahn told Il Sole 24 Ore newspaper that world economic recovery might come a quarter ahead of current expectations, adding forecasts for this country's economy will be revised upwards.

''For the (global) economy, we have been saying for a year that the recovery will come in the first half of 2010. It might even be a quarter ahead and that would be a good thing, ''We are seeing the end of the tunnel, but we are still in crisis,'' Strauss-Kahn added in the interview published on Tuesday.''

The likelihood of a recovery in the major developed countries that would be strong enough to bring the world economy back to its pre-crisis growth path in the coming years is quite low,'' the report said.

At a news conference, UNCTAD Secretary-General Supachai Panitchpakdi and senior aide Heiner Flassbeck were dismissive of suggestions that ''green shoots'' of recovery had been emerging in wealthy economies this year.

''We don't see any real rebound,'' said Supachai, former head of the World Trade Organization and one-time deputy prime minister of Thailand.

''There is no sign of a strengthening of underlying economic factors.''

UNCTAD's conclusions ran against fresh economic figures and surveys that suggested economies in the United States and Europe may be on the mend, with Chinese manufacturing also picking up speed.

''The synchronized rise in a wide range of markets that do not normally move in the same direction shows that what we have been seeing in the first half of the year is driven by speculation,'' Flassbeck told reporters in Geneva.

''What is going on is speculation on a recovery, an attempt to anticipate a recovery. But it is a fiction, it is not there yet,'' he said. ''It would be very dangerous if governments start talking about exit strategies from stimulus policies.''

UNCTAD's 181-page Trade and Development Report 2009, its main annual publication, itself said what it called the economic winter was far from over.

''Tumbling profits in the real economy, previous over-investment in real estate and rising unemployment will continue to constrain private consumption and investment for the foreseeable future,'' it said.

The upturn in financial indicators during the first half of 2009, the report added, ''is more likely to signal a temporary rebound from abnormally low levels of prices of financial assets and commodities following a downward overshooting that was as irrational as the previous bullish exuberance.''