JAKARTA, Dec 19 (Reuters) - Indonesia's government is drafting a regulation that could ease a looming export ban for not only copper concentrates, but also partly processed or raw nickel and bauxite, the Jakarta Post reported, citing a draft regulation.

Under the draft, unprocessed gold, silver, tin and chromium would remain on the export ban list, the paper said.

Energy and Mining ministry officials could not immediately be reached for comment, but a spokesman last week said the ministry was in talks with the Coordinating Ministry for Economic Affairs to try to reach a solution on easing the ban.

The ore shipments ban, which requires miners to build smelters to process ore locally and halt mineral exports from next month, was implemented in January 2014, although last minute amendments were made to ease its impact.

Traders have been closely watching the situation given Indonesia is a major producer of metals such as copper and nickel.

Helen Lau of Argonaut Securities in Hong Kong said nickel prices had been supported by a "scarcity premium" so if the ban were to be relaxed it could pressure prices.

"Nickel prices would fall because the mines will be able to export again. That will increase supply to China," said Lau, referring to the top buyer of nickel.

In October, acting mining minister Luhut Pandjaitan said Indonesia would "almost definitely" keep in place a ban on nickel ore and bauxite exports.

Asked last week about the issue as debate has continued, Pandjaitan, now a coordinating minister for maritime affairs who oversees energy and mineral resources, said there was little scope to change the export regulation until the existing law was changed.

"Even if a government regulation is issued, it will be against the law. So, we encourage parliament to review or to fix this mineral law," Pandjaitan told reporters.

However, a member of the parliamentary commission overseeing mining had said that it was unlikely a revision to the law could be concluded before the deadline.

Legal experts say if the government is unable to change the law to relax a ban it might have to use a government regulation in lieu of law, known as a Perppu.

Some mining companies have said any resumption of ore shipments could undermine metal prices and hurt investments that have already been sunk into processing plants.

But state miner PT Aneka Tambang Tbk (Antam) is lobbying to allow some exports of nickel ore because it says it needs funds for downstream investments worth at least $500 million.

(Reporting by Wilda Asmarini in Jakarta and Melanie Burton in Sydney; Editing by Richard Pullin)