Noble Group's efforts to free up capital by reducing stockpiles of base metals include selling some of its large holdings of aluminium, historically one of its biggest businesses, sources said. As part of a strategy to shrink its metals franchise, the second-biggest division by revenue after energy, Noble has been quietly selling copper, zinc and lead since July, two sources said. The company has not publicly commented on the changes or on a series of high-profile departures from the metals group. Still, company officials have privately portrayed them as a shift away from non-core, capital-intensive areas as the company focuses on its legacy strengths, which include alumina and aluminium trading. Yet the inventory reduction has also occurred in aluminium, the sources said, suggesting that the metals division shake-up may be deeper than widely known. "Inventories across all commodities have been ordered down to free up cash since [the second quarter]," one source said. He said sales of copper, lead and zinc were likely to continue as the company cuts its exposure to capital-intensive markets like copper and following the departure of the traders. But he said the aluminium business had been hit by the "meltdown" earlier this year in premiums, which are surcharges paid on top of the benchmark London Metal Exchange price for physical delivery of metal. In August, Noble blamed the second-quarter loss at its metal and mining division, the first in at least five years, on the unprecedented plunge in premiums. The metals and mining business accounted for about 20 per cent of the group's US$18 billion quarterly revenue. Rival Glencore is also offloading excess stock to help pay debt. Glencore has said it will cut its "readily marketable inventories" by US$1.5 billion and reduce working capital by an additional US$1.5 billion, partly from liquidating more inventories. It is not clear how much metal Noble has sold, but one of the sources said it had sold less than Glencore. Noble's aluminium book is considered one of the largest in the industry, competing with Glencore and Trafigura. Traders said they had not seen much evidence of Noble's sales in the market. Still, the release of unwanted stock on the market already awash with metal has likely kept premiums under pressure. US surcharges have steadied near two-year lows of 8.50 US cents a pound in recent months after plunging by more than 60 per cent since March amid concerns about waning demand from China, the world's top consumer. Noble's strategy also marks a pullback from a three-year expansion into copper, zinc and lead trading overseen by chief executive Yusuf Alireza and comes as the company battles to restore shareholder confidence after an accounting dispute since mid-February. Its shares have dropped more than 60 per cent in the past year. In August, Noble said it would lower headcount by 16 per cent and close five satellite offices by the end of the year, saving US$70 million on an annual run rate. The company was also increasing its focus on more profitable, bigger oil and gas trading, sources said. It has expanded its oil headcount from 180 to 250 over the past 18 months and sees better returns shifting barrels of crude than shipping metals over the next 12 months, a third source said. The energy division, representing the bulk of group results, more than doubled operating income in the first six months to US$482 million and almost doubled revenue to US$25.5 billion from a year ago.