Australian Environment Minister David Kemp said the birds were at risk from pollution, over-fishing of their prey and the increasing practice of longline fishing in southern oceans when the birds become hooked on bait attached to longlines and drown.

"The greatest threat is ensnarement in long-line fishing operations. Scientists estimate that thousands of seabirds have been killed from long-line fishing practices in the Southern Hemisphere in the past three years," Kemp said in a statement.

He welcomed South Africa's signing of the treaty by the High Commissioner to Australia, Ian Wilcock, at a Canberra ceremony.

Australia will act as interim secretariat for the agreement until the parties meet next year and determine a location of a permanent secretariat.

Kemp said the treaty would take effect from February 1, 2004, and allow members to implement an action plan to protect critical habitats and control threatening non-native species.

The group also plans to introduce measures to reduce the incidental catch of seabirds in long-line fisheries and support research into conservation of the birds.

There are only about 150 breeding populations of albatross around the globe and two species of giant petrels, both of which are in decline, although specific figures were unavailable.