Trade representatives from around the world start a week of talks in Brazil on Sunday, aimed at easing the impasse between rich and developing nations.
While the main event - the four-yearly UN trade conference - opens on Monday, a host of other meetings on the sidelines are getting under way.
Hopes of reaching agreement on trade failed last September at the last World Trade Organisation meeting in Mexico.
Then, developing countries refused to sign what they thought was a bad deal.
'Common ground'
Now trade ministers will be meeting on the sidelines of the UN conference to try to find some common ground.
WORLD'S POOREST COUNTRIES: MAIN EXPORTS
Sierra Leone: coffee
Tanzania: coffee
Malawi: tobacco
DRC: copper
Burundi: coffee
Zambia: copper
Yemen: oil
Ethiopia: coffee
Mali: cotton
Madagascar: coffee
Source: Oxfam
Impoverished developing countries regard present trade rules as unfair.
In particular they want more access to markets in wealthy nations and a serious reduction of European and US agricultural subsidies.
They blame these for keeping hundreds of millions of people in poverty.
While no-one expects formal agreements to be reached quickly, this is being portrayed as a make or break opportunity to set the agenda for World Trade Organisation meetings later this year.
However, some are worried that the concentration of the rich countries on the war on terrorism, along with the US presidential election, will divert attention away from reducing world poverty.
In the meantime, many developing countries will be holding talks with each other to try to reduce trade tariffs and encourage commerce amongst themselves.BBC:
