PERTH (miningweekly.com) – The world’s largest diversified miner, BHP Billiton, has again flagged the possibility of divesting its noncore assets in an effort to simplify its business model, announcing a review of its Nickel West business unit.

Speaking at a mining conference in the US, CEO Andrew Mackenzie, said that the case for the continued simplification of the company’s portfolio was “compelling”, and remained a priority.

“In the last two years, we have completed $6.5-billion of divestments at attractive valuations. We continue to study the next phase of simplification, including structural options,” Mackenzie said.

Media speculation is rife that the company is considering a $20-billion demerger plan for its noncore aluminium, manganese, thermal coal and nickel assets.

The miner on Wednesday said that it was reviewing its Nickel West business, in Western Australia, which comprise the Mt Keith, Cliffs and Leinster mines, as well as the Kalgoorlie smelter, Kambalda concentrator and the Kwinana refinery.

The review was considering the options for the long-term future of the business, including the potential sale of all or parts of the business. The review followed the decision to cease operations at the sub-level cave at the Perseverance underground mine in December last year, owing to safety concerns.

However, Mackenzie has reiterated that no firm decisions have been made on any of the other business units.

“We will only pursue options that maximise value for BHP’s shareholders,” he told delegates at the conference.

Meanwhile, Mackenzie said that BHP hoped to increased its productivity gains from the $4.9-billion achieved to date to $5.5-billion during the current financial year.

Capital expenditure, which had been reduced by 25%, would also further decline in 2015.

“By reducing the rate of investment, we have created strong competition for capital, and now expect an average rate of return of more than 20% for our portfolio of low-risk, largely brownfield development options.”