nuclear submarine trapped in the Barents Sea.

The fibre-optic cable company sent one of its submarine rescue units to help in attempts to rescue the crew of the crippled Russian submarine Kursk which sank on Saturday in the Arctic Ocean.

"We are responding with great speed to the request of the British Government and are honoured to be part of the compassionate international effort to assist in this crisis,'' said Global Crossing chairman Gary Winnick.

"I have urged all members of the Global Marine team to do whatever they can to bring the resources of our company to the relief of these sailors and their families,'' he added.

Environmentalists yesterday emphasised that the immediate radiation threat from the submarine Kursk was minimal.

Global Crossing to help rescue bid But they said it was more worrisome in the long run because it sank in rich fishing waters estimated to be about 350 feet deep.

The undersea rescue unit, part of Global Crossing's global Marine division in the UK is operating under contract to the Ministry of Defence in the UK.

Global Marine manages, maintains, and operates the manned rescue submersible LR5 for the UK Government's Ministry of Defence.