Glencore Xstrata's head of aluminium, Gary Fegel, is set to leave the company, sources said, the first high-profile departure since commodity trading giant Glencore closed its purchase of miner Xstrata this month. Fegel's departure from one of the most powerful jobs in the global aluminium market will come as a surprise to many since he was reconfirmed in the post just weeks ago, and aluminium is one of the few areas of Glencore's mining portfolio that has no overlap with Xstrata. The specific timing and reason for his exit - after 12 years at Glencore - are unclear, and discussions over possible succession continue. Fegel's comes as chief executive Ivan Glasenberg undertakes a three-month review of the division, a source familiar with the company's operations said. A successor was expected to be named this summer, about the time Glasenberg completes his 100-day review, the source added. "He's there until the merger has bedded down," said another source. A spokesman for Glencore Xstrata declined to comment. Fegel, one of Glencore's most senior executives and among its largest shareholders, has run the division alone since the departure of co-head Steven Blumgart in January last year. His exit will come as an unwelcome surprise just as Glencore begins its biggest ever integration challenge. The departure may also raise questions about the retention of top talent at the merged miner and trader. The takeover led to the departure of all but one of Xstrata's divisional heads. Glencore bosses have taken 12 of 14 top divisional jobs. Fegel is a long-time top trader at Glencore. He joined the firm in 2001, took over co-management of the aluminium division in 2006, and became a paper billionaire when Glencore went public in 2011. He now owns a 1.2 per cent stake in Glencore Xstrata, worth almost US$800 million.