Mining giant BHP Billiton has signalled its wish to spin off a chunk of the company in a demerger of assets estimated to be worth as much as 12 billion US dollars (£7.2 billion).

The group's board may announce its next move on the plans after it meets next week to hammer out the next phase of the firm's streamlining.

BHP said it wanted to concentrate on four or five major commodities - iron ore, copper, coal and petroleum and potash.

Analysts say the £44 billion firm, which is the world's largest miner by market value, will want to spin off commodities such as aluminium, manganese, and nickel, which have a lower contribution to group profit.

The giant was created out of the 2001 merger of two miners: Australia's Broken Hill Proprietary Company (BHP) and the UK's Billiton.

The move by BHP is part of a wider programme by the firm that has seen it sell off billions of assets in recent years including uranium and diamond businesses.

It is in line with the strategies of a number of global commodity groups that have shed assets to bolster profits amid a downturn in commodity prices, appeasing investors seeking higher returns.

The market expects BHP chief executive Andrew Mackenzie to report a sharp rebound in BHP's full-year profits next Tuesday, by 27% to 13.9 billion US dollars (£8.3 billion) from 12 months ago, and a possible share buyback to boost shareholder returns.

Brokers said a spin-off from BHP would be complicated as the firm is listed in London and Australia, and management would have to work out how to distribute the shares to investors evenly.

BHP said: "A demerger of a selection of assets is our preferred option. The Board expects to consider this, and other matters, when it reconvenes next week. If any material decisions are made, they will be announced immediately."