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…