Traders work on the floor of the London Metal Exchange in London, Britain, September 27, 2018.
Traders work on the floor of the London Metal Exchange in London, Britain, September 27, 2018. Reuters / Simon Dawson

Fund manager Elliott Associates has sued London Metal Exchange (LME) for $456 million following the suspension and cancellation of nickel trades on the platform owned by Hong Kong Exchanges and Clearing Ltd, the Hong Kong bourse said on Monday.

LME and LME Clear Limited have been named as defendants in a judicial review claim filed in a British court by Elliott Associates and Elliott International in early June, LME's parent HKEX said in a filing.

The hedge fund seeks to challenge LME's decision to cancel its trades in nickel contracts executed on or after 00:00 British time on March 8, the filing says.

The LME suspended activity and cancelled nickel trades on March 8 due to volatility that saw prices double to more than $100,000 a tonne within hours.

A spate of technical glitches after trading resumed on March 16 left traders fuming.

Elliot Associates claims the trade cancellation was "unlawful on public law grounds" and "constituted a violation" of its rights, according to the filing.

HKEX said the LME dismissed the claim in its statement. "The LME management is of the view that the claim is without merit and the LME will contest it vigorously," HKEX said.

HKEX shares were up 0.6% by 0400 GMT on Monday, slightly underperforming while the broader market index was up more than 1%.

The LME has come under spotlight from European regulators following the nickel trading debacle. It has led regulators and industry players to call for greater scrutiny on opaque corners of the commodities market.

Last month, the LME proposed measures that it said would improve transparency and stability in the over-the-counter (OTC) metals market, including more frequent disclosures of all positions.

Its rival CME Group has started talking to market participants about the idea of a cash-settled nickel contract for companies, sources told Reuters last month.