* Polyus aims for up to 15 pct of global antimony market
* Metal used primarily in fire retardants, batteries
* Polyus has sales contracts for all 2018 antimony output
* The first supply will be delivered to China
MOSCOW, March 20 (Reuters) - Russia's largest gold producer Polyus plans to start selling antimony, targeting up to 15 percent of global output of the metal used primarily to make fire retardants and batteries.
Its decision coincides with rising prices of the metal <ANT-LON>, which is trading in Europe at its highest level since June, around $8,700 a tonne, due to tight Chinese supply.
Polyus, controlled by the family of Russian tycoon Suleiman Kerimov, said it will produce the metal at its large Olimpiada gold deposit in Russia which has reserves of high-content antimony ore.
"We are going to be a significant player in the antimony market," Polyus Chief Financial Officer Mikhail Stiskin told the company's capital markets day in London.
China, Japan and South Korea are the world's top antimony consumers.
Polyus said it has already signed sales contracts for all of its 2018 production of the metal and is preparing to make its first delivery, to China.
Global production of antimony was estimated at 150,000 tonnes in 2017, United States Geological Survey data shows. More than 70 percent of that was produced by China, which has been tightening environmental regulations and beefing up its monitoring capabilities.
Polyus said it plans to produce concentrate containing 200,000 troy ounces of gold annually and 15,000-20,000 tonnes of antimony. The total amount of high content antimony ore to be mined at the Olimpiada deposit between 2017 and 2026 is estimated at 11 million tonnes.
The antimony project will also allow Polyus to reduce its total cash costs by $10 to $15 per ounce, the company added.
Earlier on Tuesday the company said that its total cash cost would be below $425 per ounce in 2018 and below $450 per ounce in 2019-2020. (Reporting by Polina Devitt and Diana Asonova; Addiitional reporting by Nallur Sethuraman; Editing by Polina Ivanova and Susan Fenton)