The bell, which was recovered from the wreck off Donegal in 1979 by Londonderry recreational diver Ray Cossum, has been acquired for display by Derry & Strabane District Council.
More than 350 people died when the Laurentic sank 100 years ago, in January 1917, after striking two mines laid by a German U-boat at the mouth of Lough Swilly.
The 172m vessel, built in Belfast in 1908, had been converted into an armed merchant cruiser at the start of WW1, and was bound for Nova Scotia carrying more than 3000 gold ingots to pay for war munitions.
Most of the gold, worth around £400 million at today's prices, was recovered in the years following the sinking.
The war grave lies at a depth of around 40m. The bell, which was previously owned by Bembridge Maritime Museum in the Isle of Wight, is intended for display in a maritime museum planned for the Ebrington tourist attraction in Derry.
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