Unions have called on mining giant BHP Billiton to guarantee entitlements and enterprise agreements for workers affected by its demerger.

 BHP plans to offload the majority of its aluminium, manganese, nickel and silver assets into a new company that is to be listed on the Australian share market by mid-2015.

Assets selected for the new company include Illawarra Coal in NSW, Queensland’s Cannington silver mine, a manganese mine in the Northern Territory and an alumina refinery in Western Australia.

Australian Workers’ Union National Secretary Scott McDine will meet with management to ensure guarantees are provided around the transfer of all employee entitlements to the new company.

The union wants all current negotiated enterprise agreements to be maintained, and it will seek assurances from the company about its investment plans for current BHP sites and operations that will now fall under control of the new company.

BHP is now focusing on its four core areas – iron ore, coal, copper and petroleum after a 23 per cent increase in its full year profit to $US13.8 billion ($A14.93 billion).