UK Seabed Resources is a subsidiary of the British arm of Lockheed Martin. It has plans for a major prospecting operation in the Pacific.
The company says surveys have revealed huge numbers of so-called nodules - small lumps of rock rich in valuable metals - lying on the ocean floor south of Hawaii and west of Mexico.
The exact value of these resources is impossible to calculate reliably, but a leading UN official described the scale of mineral deposits in the world's oceans as "staggering" with "several hundred years' worth of cobalt and nickel".
An expedition to assess the potential environmental impact of extracting the nodules will be launched this summer amid concerns that massive "vacuuming" operations to harvest the nodules might cause lasting damage to ecosystems.
With the support of the British government, UK Seabed Resources has secured a licence from the United Nations to explore an area of seabed twice the size of Wales and 4,000m deep.
Under the UN's Convention on the Law of the Sea, mining rights on the ocean floor are controlled by a little-known body, the International Seabed Authority, which since 2001 has issued 13 licences - with another six in prospect.
These licences, valid for 15 years, have been bought for $500,000 each by government organisations, state-owned corporations and private companies from countries including China, India, Russia, Japan and South Korea.