MOSCOW, May 21 (Reuters) - Russia's largest oil producer

Rosneft acquired Tomtor, country's largest rare earth

metal deposit, a companies registry showed on Wednesday, after

President Vladimir Putin last year urged that the development of

the field be speeded up.

Tomtor, located in the north of the Siberian region of

Yakutia, is a key project in Russia's plans to boost output of

the metals that are used in the defence industry and in making

mobile phones and electric cars, to reduce reliance on imports

from China.

According to an official state registry of Russian

companies, Rosneft secured complete control over the project's

operator, Vostok Engineering, on May 20.

Rosneft did not immediately reply to a request to comment.

In November Putin accused the operator of Tomtor of delaying

the deposit's development, suggesting it should either raise

investment or seek help from third parties, including the state.

Before the Ukraine conflict, Russia planned to invest $1.5

billion in rare earth minerals, striving to become the biggest

producer after China by 2030.

Other countries, including the United States, are also

trying to curb their reliance on China, which controls 95% of

the global production and supply of rare earth metals.

Businessman Alexander Nesis, a former shareholder in

Polymetal, a major producer of gold and silver, used to own a

75% stake in a firm called ThreeArc Mining, the operator of the

project, through his IST group of companies.

Polymetal used to own a 9.1% stake in ThreeArc Mining.

Following the ownership change after the start of Russian

military action in Ukraine, and subsequent Western sanctions on

Russian businesses, the operator of the project ended up under

control by IST's former manager Vladislav Resin, before Rosneft

gained it.