* Australia's Port Hedland to shut as cyclone looms
* Port's major users are BHP, Fortescue
* Second storm on other side of Australia halts zinc shipments
Australia's Port Hedland, a major terminal for iron ore exports, will shut down operations on Tuesday due to a tropical storm threatening the country's far west coastline.
Port Hedland is used by BHP Billiton , Fortescue Metals Group and Atlas Iron to ship ore, currently at a rate of around 200 million tonnes per year, accounting for a fifth of global seaborne trade in the steel-making raw material.
Iron ore prices have gained support from concerns that Australia's cyclone season, which runs from November until April, will reduce supplies.
Loading operations at the port had been taking place as normal early Tuesday, but ships waiting to dock were evacuating to safe waters as the tropical low, which is predicted to reach cyclone strength on Wednesday, makes its way toward the port.
"An official port closure time will be disseminated later today," the Port Hedland Port Authority said in a statement emailed to Reuters.
The last of the ships anchored within the port's inner harbour will set sail by 0730 GMT, according to the authority.
A second storm in Australia's northeast has temporarily halted shipments of zinc concentrate from one of the world's biggest mines, owned by China's MMG Ltd..
The storm in Western Australia is forecast to intensify to a Category 1 cyclone -- the weakest on a scale of one-to-five -- early Wednesday, and gales of up to 100 kph (60 mph) could develop between Pardoo and Dampier, according to the Australian Bureau of Meteorology.
Total iron ore shipments from Port Hedland in December reached a monthly record 26 million tonnes.
A cyclone that intensified 11 days ago several hundred kilometers south of Port Hedand shut ports handling nearly 200 million tonnes of ore shipped annually by Rio Tinto and cut supplies of natural gas and oil.
Rio Tinto said it was monitoring the movements of the latest storm and at this stage if a cyclone forms, it will not occur until the low has moved some 200 km (125 miles) south of Port Hedland, based on current weather forecasts.
ZINC SHIPMENTS AFFECTED
Most of the iron ore is contracted by Chinese steel mills, with Japanese and South Korean mills also big buyers.
Before the last cyclone, Woodside Petroleum, Apache energy and BHP disconnected oil production vessels from offshore fields that contribute about a third of Australia's oil production of 390,000 barrels per day..
A separate tropical storm in Australia's far north east that briefly reached cyclone strength forced China's MMG Ltd, to temporarily halt shipments of zinc concentrate from its Century mine.
The storm crossed the Queensland state coastline, bringing heavy rain and wind gusts of up to 100 kph.
MMG has also restricted zinc processing at its mine, located about 300 kms (185 miles) from the port of Karumba, according to a company spokesperson..
"Depending on the weather, we expect to resume shipping on Wednesday," the spokesperson said.
The Century mine has an annual production capacity of 500,000 tonnes, making it the second-biggest zinc mine globally.
The storm is forecast to moving further inland before tracking south on Wednesday, forecasters said.