* Rinehart sued by late father's partner Wright Prospecting
* Wright seeking half Rinehart's stake in lucrative iron ore tenements
* Rinehart also battling children over multi-billion dollar family trust
PERTH, Sept 27 (Reuters) - Asia's richest woman Gina Rinehart is fighting a fresh court battle over iron ore assets in Western Australia worth billions of dollars, the latest in a series of legal scraps involving the mining magnate that have generated much local media buzz.
Rinehart's Hancock Prospecting Pty Ltd is being sued by Wright Prospecting Pty Ltd, her late father's business partner, which is seeking part of her company's interest in iron ore tenements now half-owned by Rio Tinto Ltd, according to documents filed in the Supreme Court of Western Australia.
Rinehart's father Lang Hancock and Peter Wright discovered vast tracks of iron ore in the Pilbara in the 1950s and owned tenements jointly through a partnership known as Hanwright. But disputes over ownership have raged between the prospectors' descendants for years.
In the latest case, Wright Prospecting is staking a claim of half of Hancock Prospecting's ownership in three tenements known as Hope Downs 4, 5 and 6, according to a writ filed with the court on Monday.
"The Hanwright partnership owned these tenements jointly in 1970s... Wright Prospecting is now trying to recover its interest in those tenements," a spokesman for Wright Prospecting said in an emailed statement to Reuters on Thursday.
Wright claims that the tenements were re-awarded to the Hanwright partnership and held by Hancock on Hanwright's behalf.
"We don't understand the writ after Hancock Prospecting, without Wright Prospecting, have held the Hope Downs tenements 4, 5 and 6 for more than 20 years and Wright Prospecting have not contributed towards them financially in this period," Hancock Chief Financial Officer Jay Newby told Reuters in an email.
Rio and Rinehart's Hancock are currently developing Hope Downs 4, which will have an annual capacity of 15 million tonnes of iron ore, worth close to $1.5 billion at current prices, when it begins production next year.
Rio bought half of the three tenements in 2005.
"Wright Prospecting were timely aware of the transaction that year, some seven years ago, and chose not to dispute ownership of the tenements," Newby added.
Hancock is currently trying to secure funding to develop another large iron ore mine, rail and port project called Roy Hill. That project is facing delays due to tumbling iron ore prices and a bitter family feud.
Rinehart, whose fortune was estimated by Forbes at around $18 billion earlier this year, is fighting three of her adult children over control of a $4 billion family trust.