UPDATE 4-Trade assistance could reignite growth, help the poor

* U.N. secretary-general says trade can stimulate recovery

* WTO says trading environment has worsened dramatically

* World Bank, IMF says exporters must be ready for rebound

* OECD sees less financing stress, Standard Chartered upbeat

(Adds quotes from OECD, Standard Chartered interviews)

By Laura MacInnis

GENEVA, July 6 (Reuters) - International trade could ignite and propel a global economic recovery, top United Nations and multilateral lending officials said on Monday.

At a World Trade Organisation conference on aid-for-trade, World Bank President Robert Zoellick said that poorer countries whose exports have fallen sharply need to be ready to ship their wares again once the downturn bottoms out.

"Trade was one of the first sectors decimated by contracting consumption in high-income countries. But it will also be one of the first sectors to recover once the global economy picks up steam," Zoellick told diplomats at the WTO's headquarters.

"Those countries that position themselves now to take advantage of renewed trade will accelerate out of recession with the fastest momentum," he said, calling trade one of "many planks upon which recovery will be built."

U.N. Secretary-General Ban Ki-moon took it a step further, saying rebounded commerce "had tremendous potential as an engine of sustained economic growth and development."

"Trade can and must be part of our efforts to stimulate a recovery," Ban told the conference.

Efforts to improve roads, upgrade electrical grids and speed up customs procedures can put developing countries in a stronger position when the economy does rebound, the U.N. chief said in remarks later echoed by the International Monetary Fund.

"Trade can start up quite quickly, as quickly as growth, once the recovery starts in developed countries," IMF Managing Director Dominique Strauss-Kahn said, calling for targeted aid to ensure poor-country exporters were primed for a rebound.

Aid-for-trade was promised to poorer nations in 2005 during negotiations over the Doha Round, a global free trade deal that WTO Director-General Pascal Lamy hopes to wrap up next year.