(FILES): This September 15, 2008 file photo shows the sign for Lehman Brothers headquarters in New York.  The 158-year-old Lehman filed for bankruptcy protection on September 15, 2008 in the largest US bankruptcy filing in history, leaving the future of 25,000 staff in jeopardy and sending a financial tsunami across the globe that continues to reverberate today.    AFP PHOTO / Files / Nicholas ROBERTS / AFP / AFP FILES / NICHOLAS ROBERTS