SYDNEY (Reuters) - Australian Gina Rinehart could soon become the world's wealthiest woman after amassing an $18 billion fortune from mining and media investments, Forbes magazine says in its latest list of the wealthiest people in Australia.
The 57-year old widow saw her fortune almost double after a deal signed last month that will see South Korean steel giant POSCO take a 15 percent stake in her Roy Hill iron ore mine in Western Australia's Pilbara iron belt.
The deal valued the project at $10 billion, boosting Rinehart's fortune dramatically.
In the next few years, Rinehart also has plans to expand her iron ore operations and develop two coal collieries.
If commodity prices hold up, Rinehart could challenge Christie Walton, worth $24.5 billion, as the world's richest woman, Forbes said.
Walton is the widow of John Walton, one of the sons of Sam Walton, the founder of retail chain Wal-Mart Stores.
For now, Rinehart will have to be content with being the Asia-Pacific region's wealthiest woman, based on Forbes' tally.
Rinehart is the daughter of Lang Hancock, an Australian prospector credited with discovering giant deposits of iron ore in the 1950s that now make up Australia's largest export base.
China alone relies of Australian iron ore for nearly half its imports of the key steel making ingredient, and Japan, South Korea and Taiwan also are big buyers for their steel mills.
Compared with other ultra-rich like Microsoft founder Bill Gates and Facebook's Chief Executive Mark Zuckerberg, the source of most Rinehart's wealth is downright low-tech.
Iron ore is just extracted from giant pits resembling excavation sites found in the 500,000-square-kilometer, or 190,000-square-mile, Pilbara, the single largest source of iron ore in the world. Ore is simply churned up by bulldozers and carted in trucks to waiting open-topped rail cars.
Known as the "Pilbara Princess," Rinehart is also building stakes in some of Australia's largest media companies, drawing comparisons to another famously powerful Australian, Rupert Murdoch, head of News Corp and now a U.S. citizen.
Rinehart this week became the largest shareholder in Fairfax Media by more than tripling her stake in the newspaper, digital and radio broadcasting company. She already owns 10 percent of rival Ten Network Holdings.
Her move into media is raising concerns among politicians, namely the left-leaning Labor party of Prime Minister Julia Gillard, whose views on who should control the Australian mining sector differs from Rinehart's.
"It has always been the case in Australia over my lifetime in politics that a small number of families have had a controlling interest in the majority of the media in this country," Communications Minister Stephen Conroy said.
"All that's really changing is that a different wealthy individual is taking a strategic or ownership position in some media," he said.
"Clearly she is seeking to exert her influence," he said.
Opposition party treasurer Joe Hockey, whose political party bent is more in line with Rinehart's conservative views, has called her simply "a good person, a good Australian."
In a rare public display, Rinehart joined another Australian billionaire, Andrew "Twiggy" Forrest, to protest against the government's introduction of a special mining tax and was heard chanting "Axe the Tax."
On the environment, Rinehart is also at opposites with Gillard, who introduced a carbon tax.
Her views on how to tackle greenhouse gas would make climate activists such as Al Gore wince.
"What good will adding a carbon tax do in Australia?" Rinehart wrote in an industry journal last year in comments published in the Australian newspaper.
"Will a tax in Australia bring down carbon dioxide emissions elsewhere? No."
She is also outspoken on Australia's immigration policies, arguing miners should be allowed to bring in cheap labor.
Rinehart is regarded as iron ore's princess because her father -- who she is said to emulate in many of his conservative views -- was the undisputed king, who drew loyal subjects and detractors in equal measure.
But since his death in 1992, Rinehart as executive chairman of Hancock Prospecting Pty Ltd almost single handedly transformed the family owned company into an international force.
Stories of her father's role in establishing an asbestos mine, dealings with the brutal Romanian dictator Nicolae Ceausescu and harsh views on the unemployed are often repeated.
Rinehart, although reportedly fiery and unlikely to suffer fools for long, is said to abhor emotional outbursts in her employees and applauds a cool head.
She also has financially contributed to a range of social causes in sport, health and medical research, including the Hancock Family Breast Cancer Foundation.
Rinehart avoids media interviews, especially now as she fights to keep details of a family legal battle out of the public eye.
Three of her children are trying to oust her as trustee of a multi-billion-dollar family trust, set up by her father before he died.
Little is known about the family feud as a number of suppression orders have prevented the reasons becoming public.
Additional reporting by Miranda Maxwell in Melbourne; Editing by Ed Davies