Britain has been criticised by bird conservation groups for not ratifying a global treaty to protect the albatross, which comes into force on Sunday.
A number of albatross species are said to be at risk of extinction
Under the accord, action will be taken against long fishing lines, often used to catch tuna but which kill about 100,000 of the seabirds every year.
Britain's participation is important because its overseas territories of the Falklands, South Georgia and Tristan da Cunha are breeding grounds for the bird.
It has been ratified by Australia, Spain, Ecuador, New Zealand and South Africa.
The UK Government signed the Agreement on the Conservation of Albatrosses and Petrels (ACAP) three years ago but is thought to be trying to overcome international legal problems.
Reducing seabird by-catch
The ACAP means fishing vessels using the waters of ratifying countries will be obliged to take measures to reduce seabird by-catch.
Dr Euan Dunn, of the Royal Society for the Protection of Birds and BirdLife International, said: "This is a massive step forward in efforts to curb the senseless slaughter of these majestic birds and signatory countries now have no choice but to take steps to get them off the hook."
Measures to be taken to reduce seabird by-catch include setting lines at night, deploying bird-scaring streamers, and weighting lines so that the baited hooks sink more quickly.
The five states involved will also be required to protect the birds' breeding grounds, reduce habitat loss and tackle marine pollution in the waters under their jurisdiction.
Dr Dunn said the measures must be much more widely adopted to save the birds from extinction.
"The UK has a major responsibility because its overseas territories, particularly Tristan da Cunha, South Georgia and the Falklands, are vitally important to populations of globally threatened species.
"Until the UK and its Overseas Territories ratify ACAP, they will be mere observers and unable to influence action taken under the treaty."
According to BirdLife International, two albatross species are classed as critically endangered, three as endangered and a further 12 as vulnerable.