Representatives from most of the world's nations have reached agreement on an international treaty that would control the export of hazardous waste.

U.N. Undersecretary-General Mostafa Tolba, speaking after two days of intensive ministerial-level negotiations, said early Wednesday he expected the 116 nations present to adopt the convention by consensus later in the day.The convention would ban the export of hazardous waste - which can cause cancer, birth defects and many other health problems - to countries not equipped to handle it properly.

The treaty, the product of 18 months of negotiations, aims to curb what African nations call "garbage imperialism," or the dumping of the West's waste in the Third World.

A smaller number will actually sign it because many delegates must take the document back to their governments for examination first.

"I am very happy, because we did achieve something which I considered extremely difficult," Tolba, an Egyptian scientist, told reporters.

Several amendments to tighten the convention were approved late Tuesday and no further objections were raised.

But watchdog organizations were not happy.

Environmentalists charged that the treaty left many loopholes and was rushed through simply to meet Wednesday's scheduled signing. Government delegates argued it was the best that could be achieved in a North-South tug-of-war.

"Some day some child in a developing country will get sick and we will explain to him that we didn't have time to fully consider all the issues," said Allen Hershkowitz of the U.S.-based Natural Resources Defense Council.

"The convention is going to institutionalize a certain level of waste trade regardless of environmental concerns," Greenpeace delegate Jim Vallette told Reuters.

African nations were the most vociferous in demanding tighter restrictions, but in the end several said the result was a good beginning.

"Ninety percent of what could be done has been done," Kenyan Environment Minister J.J.M Nyagah told Reuters. "We have something to build on."