A Malaysian court Wednesday ordered a further delay in the opening of an Australian-owned rare earths plant, following protests from residents worried about possible radiation pollution.

Lynas Corp in early September secured a temporary operating licence for its plant and announced plans to begin operations this month.

But on Wednesday the Kuantan High Court, on the east coast where the plant is based, extended an interim stay on the licence till November 8.

Activists said the court would rule that day on whether to suspend the operating permit pending a judicial review of the decision to approve the plant.

Environmental group Save Malaysia Stop Lynas (SMSL), which is spearheading the protest, said the postponement was a "small consolation" for its efforts to stop the plant.

The Sydney-based firm has since early 2011 faced protests by environmentalists and residents concerned about radiation pollution, delaying initial plans to open the rare earths processing plant by October last year.

"The court heard arguments from all parties for over four hours. The judge reserved her decision until November 8 and pending that, the interim stay is extended," SMSL chief Tan Bun Teet told AFP.

Activists and local residents have vowed to shut the plant, the biggest outside China. It has become a political issue before national elections, which must be held by the middle of next year.

China currently supplies about 95 percent of the world's rare earths, used in high-tech equipment from iPods to missiles. Lynas hopes the Malaysian plant will help it break the Chinese dominance of the market.

It will process material from Lynas's Mount Weld mine in Western Australia.

Lynas has insisted that any radioactive waste to be produced by the plant will be low-level and not harmful to humans.

But opposition politicians and environmentalists have expressed fears that such waste could seep into the ground and water, harming the environment and people's health.