To operate a successful aluminum maker requires secure access to bauxite, the raw material of alumina; cheap energy, by far the dominant manufacturing cost; and dependable customers. United Co. Rusal appears to have all three in abundance, which explains why it is the world’s largest aluminum producer.

But there’s another critical factor: ample financing. And there, Rusal’s controlling shareholder and CEO, Oleg Deripaska, has been struggling. Once the richest of Russia’s oligarchs, Deripaska ran up massive acquisition-related debts in recent years only to have the economic crisis imperil his financial position. In an effort to lighten its debt load, on January 27, Rusal raised $2.24 billion by floating a 10.6 percent stake in an initial public offering on the hot...