Britain and the US have signed a treaty to protect the wreck of the Titanic, which sailed from Southampton, from looting.

The treaty would set up regulations to control visits to the site, located in international waters about 225 miles off the coast of Newfoundland.

Assistant Secretary of State John Turner said: "It also designates the Titanic as an international maritime memorial, and would set up a system for any items taken from the wreck to be properly curated and available for the public to view."

The agreement came at the urging of undersea explorer Robert Ballard, who first found the Titanic 18 years ago.

He revisited the site this month to chronicle damage to the wreck, caused both by natural forces and by visitors and salvagers.

He said that visiting submarines have landed on the wreck repeatedly, and salvagers have taken many items from the site.

He said France, Canada and Russia should also sign the treaty, because they are the only other nations which have the capability of visiting the site by submarine.

Ballard said: "I'm encouraged now to see the momentum picking up, and I think several things would need to go on before I could call the Titanic safe, but it's absolutely the right thing to do."

The liner sank on April 15, 1912, during its maiden voyage from Southampton to New York after hitting an iceberg.

About 1,500 people died and the ship now rests at the bottom of the sea, 2.5 miles down.

- Originally published June 2004.