In July, a month before the bailout of BES, Goldman structured a Luxembourg-based special purpose vehicle for the lender called Oak Finance, buying up its bonds with the intention of selling them on at a profit to investors, a person familiar with the deal said. Goldman declined to comment.
However because of investor concerns over problems at BES, Goldman was unable to sell on large amounts of the debt, meaning it was left holding the bonds exposed to the lender when the Portuguese central bank took control of the bank and split it up at the start of August.
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After structuring the vehicle, which was first reported by the Wall Street Journal, Goldman managed to sell on an unknown quantity of the bonds to distressed debt investors before the bank was rescued. It is unclear how much the US investment bank stands to lose from the transaction.
The Goldman-linked debt has been placed within the so-called "good bank" created as part of BES's rescue, which would indicate the Portuguese authorities believe that there is some chance of part of the loan's being recovered.
BES, which had been 25 per cent controlled and managed by descendants of the man who founded the bank out of a Lisbon lottery stand in the 1860s, was brought down in part by its large exposure to the debts of the various holding and industrial companies of the Espírito Santo family, including the privately held Espírito Santo International (ESI).
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These Luxembourg-registered family holding companies, which filed for bankruptcy protection before the rescue of the bank, had for at least several years helped finance themselves by selling their own debt to clients of BES.
By November last year the Portuguese market regulator tightened rules on banks selling debt to retail investors that was linked to their own parent companies, meaning BES was forced to find new ways to finance itself in deals such as the Goldman transaction.
It was also in the closing months of last year that "serious accounting irregularities" were first detected at ESI. The Bank of Portugal had commissioned PwC to look into the future cash flows of 12 non-financial Portuguese groups to ensure they could service their bank loans.