Executives of Citigroup Inc. say the giant bank has secured funding through year end for the $80 billion in structured investment vehicles it manages after selling $20 billion in assets since the midsummer credit crunch. The steps taken by the bank's alternative-asset management unit, run by former Morgan Stanley stock-division chief John Havens, mean the Citigroup SIVs can avoid the kind of forced selling at distressed prices begun by some other European SIV managers, the executives said.