SHANGHAI (Reuters) -Shares of Chinese battery makers plunged on Friday after the country announced that it would control exports of lithium battery parts, a move that tightens its grip on the technology critical for energy storage and electric vehicles.

It had earlier expanded export controls over rare earths as trade tensions with the United States simmer ahead of a possible meeting between Presidents Donald Trump and Xi Jinping later this month.

Beijing's export control on some high-end lithium-ion batteries, cathodes and graphite anode material as well as technological know-how will require exporters to seek permits and set to take effect from November 8, per a Ministry of Commerce statement on Thursday. On Friday, battery maker Contemporary Amperex Technology Co Ltd. (CATL) tumbled 6.82%, Tianqi Lithium sank 7.17%, EVE Energy slumped nearly 11%, while BYD dropped 2.54%, as of market close.

"The new controls drastically expand how much of the lithium battery supply chain China is staking a claim to," said Cory Combs, head of critical mineral research at Trivium China.

"Foreign producers or Chinese overseas joint ventures are at risk should Beijing choose to slow-walk and limit export licenses."

However, analysts at Zaoshang Securities said the controls are unlikely to result in a ban and will have limited impact as exporters will only have to go through a short process.

Previous rounds of controls on items like natural graphite did not result in a major drop in exports, they added.

Chinese companies have invested in plants in North America, Europe and Southeast Asia, including the Ford-CATL plant in the U.S., which are reliant on Chinese inputs.

Shares were also hit by a revision to China's electric vehicle tax exemptions, also released on Thursday, that tightened eligibility for exemptions.

China's New Energy Vehicles Index fell 6.02%.