Mack declined to comment on the impact of Sechin's sanctioning. ("I have no thoughts on that," he said.) Still, Mack's departure from the Rosneft board is awkward for another reason: The attempts of his former employer, Morgan Stanley, to sell its oil merchant unit to the Russian driller.
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As part of a broader disposition of its physical commodity holdings, Morgan agreed last December to sell the oil-sales division for an undisclosed sum. But the deal requires approval by the U.S. Committee on Foreign Investment, a multi-agency panel that could be dissuaded to do the deal by the government's current standoff with Russia over its behavior toward Ukraine, whose Crimean peninsula it recently annexed.
Morgan Stanley officials have said they hope to win approval for the Rosneft transaction and complete it by the end of September. The bank is in the midst of preparing its paperwork for CFIUS and has not formally submitted its request yet, according to someone familiar with the process.
Mack was replaced by James Gorman as CEO of Morgan Stanley early in 2010, but remained its chairman until the end of 2011.
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Since then, his time has been consumed by a board membership at the Swiss commodity trader Glencore Xstrata, where he has been a director since last year, his consulting work at the private-equity firm KKR, where he is a senior adviser, and his consulting with New York state Gov. Andrew Cuomo on some economic-development issues, among other things. His brief tenure on Rosneft's board, he said, was a fascinating experience: "It's probably the largest energy company in the world, and very dynamic in what (it's) doing."
Rosneft's board includes several directors from outside Russia, including Robert Dudley, the American-born CEO of the British driller BP, which owns a nearly 20 percent stake in the Russian driller, and Donald Humphreys, a former chief financial officer of Exxon Mobil. A BP spokesman said Dudley had no plans to leave the Rosneft board, and an Exxon Mobil spokesman declined to comment on Humphreys' behalf. Company spokespeople for Rosneft, who revealed Mack's resignation to a Reuters reporter earlier Thursday, were not immediately available for comment.