BHP Billiton chairman Jac Nasser has talked up the benefits of a multi-billion dollar plan to spin off some of the mining giant's less profitable assets.

Addressing shareholders at BHP’s annual general meeting, Mr Nassar said demerging the aluminium, nickel, silver and coal assets would benefit other parts of its global operations. The rationale for the split was BHP’s portfolio had evolved into what the company saw as two distinct companies, he said. BHP’s focus was…