Rusal, the world's largest aluminium producer, has triggered a judicial review of plans by the London Metal Exchange to reform how it stockpiles commodities, the LME's owner said on Tuesday.

Russian company Rusal filed a claim in the English High Court on Monday, the Hong Kong Stock Exchange said in a statement. The Hong Kong bourse last year bought the LME, which is the world's biggest metals exchange.

Rusal opposes a plan to expedite deliveries of base metals, in particular aluminium, that are traded on the LME.

The plan announced in November is aimed at benefiting consumers and boosting the LME's market credibility. But producers have strongly opposed the plan.

According to Tuesday's statement, "LME management considers that the grounds of Rusal's complaint are without merit, and will defend any judicial review proceedings vigorously".

It noted that "the judicial review seeks to challenge the LME's decision to introduce changes in its warehousing policy" that followed a three-month consultation.

"Rusal has alleged that the consultation conducted by LME was unfair and procedurally flawed, that the LME's changes to its warehousing policy are irrational and disproportionate, and that Rusal's human rights have thereby been breached," the statement added.

Despite the judicial review, "implementation of the proposed changes to the warehousing policy will proceed as announced" -- from April 2014 -- it added.

Warehouse bottlenecks have occurred after metals like aluminium became a financing tool in the wake of the 2008 global financial crisis.

Producers sold or pledged metal to traders and banks to raise much-needed working capital, with the result that the aluminium was locked up in warehouses, rather than finding its way to companies needing base metals to make goods.

Meanwhile, cheap financing and an aluminium market where future prices exceed current prices meant banks could lock in an easy profit. In addition, premiums paid for more immediate access to base metals have soared, raising buyers' costs.