Nickel prices climbed to its highest level in a month on Wednesday, outperforming its base metal peers, as Indonesia confirmed a ban on exports of unprocessed ores remained in place.

Metal for delivery in three months on the London Metal Exchange rose 3.2% to $16,149 a tonne, extending gains over the past two and half weeks to 9.6%, after Bambang Adi Winarso, a senior adviser to the co-ordinating minister for economic affairs, announced the ban extension.

Ore from Indonesia —the world’s No. 1 nickel producer— is used for generating about 30% of the global nickel supply, which in turn is used to make stainless steel.

Most of it is sent to China, where is processed into nickel pig iron (NPI), a cheap alternative to pure nickel.

The country effectively halted all but processed metal shipments in January in an effort to force miners to build smelters, winning the country bigger returns from exports of its mineral resources.

• [Editor:Juan]