The robot is ready - so when will deep sea mining start?

(Repeats story first published April 18, text unchanged)

* Most potential subsea minerals in international waters

* U.N. body expects mining code in 2-3 years

* Canadian company ready to mine off Papua New Guinea

By Stephen Eisenhammer and Silvia Antonioli

NEWCASTLE, England/LONDON, April 18 (Reuters) - The world's first deep sea mining robot sits idle on a British factory floor, waiting to claw up high grade copper and gold from the seabed off Papua New Guinea (PNG) - when a wrangle over terms is solved.

Beyond PNG, in international waters, regulation and royalty terms for mining the planet's subsea wealth have also yet to be finalised. The world waits for the judgement of a United Nations agency based in Jamaica.

"If we can take care of the environment we have a brand new day ahead of us. The marine area beyond national jurisdiction is 50 percent of the Ocean," said Nii Odunton, secretary general of the U.N.'s International Seabed Authority (ISA).

"I believe the grades look good, the abundance looks good, I believe that money will be made," Odunton said from the ISA offices in Kingston.

High-tech advances, depleted easy-to-reach minerals onshore and historically high prices have boosted the idea of mining offshore, where metals can be fifteen times the quality of land deposits.

In Newcastle, the "beasty", as engineer Keith Franklin calls his machine, lies in wait, resembling a submersible tank with four metre wide cutting blades.

Built by Soil Machine Dynamics (SMD), it will put Canadian listed Nautilus Minerals on course to become the first company to commercially mine in deep water.

Nautilus' primary resource, Solwara 1, about 1,500 metres underwater, is a Seafloor Massive Sulphide (SMS) deposit, which forms along hydrothermal vents where mineral-rich fluids spurt from cracks in the ocean crust.

Equipped with cameras and 3D sonar sensors the robot is driven by two pilots from a control room on the vessel above, attached via a giant power cable.

"The cameras aren't enough by themselves because the machine will be working by vents where black soot spurts from the ocean crust and it will sometimes be near impossible to see anything," said Stef Kapusniak, business development manager for mining at SMD. "The 3D sonar will allow it to make images and send it back to the control room."

The machine then cuts up the sea floor and sucks the rocks through a pipe to deposit it in mounds behind - "like icing a cake," Kapusniak said. Another machine, yet to be built, will then help suck the ore to the surface.

Nautilus aims to produce 80,000-100,000 tonnes of copper and 100,000-200,000 ounces of gold - equivalent to a modest onshore mine. It was supposed to be producing by now, but disagreements with the PNG government over financial terms have set it back.