called the Doha Development Agenda after the city in Qatar where it was launched -- should actually benefit poor countries. In a letter he sent to trade ministers on Sunday, Mandelson urged rich countries to open up their borders completely to exports from the world's poorest nations, among other measures. Given the scant progress so far, many trade specialists have said there is a risk that the talks in Hong Kong could fail, as have other key WTO meetings in recent years. "Agriculture and market access is the signal others are waiting for to make progress at Hong Kong," Mandelson said. --more 2340 Local Time 2040 GMT