The Securities and Exchange Commission has thrown out a lifetime securities industry ban by the NASD against Frank Quattrone, the former star investment banker at CSFB, just four days after his conviction on obstruction and witness tampering charges was overturned . The SEC said the NASD "did not act in accordance with its own rules" when it made the ban in November 2004. The ban stemmed from what the NASD called Quattrone's "egregious" misconduct in refusing to testify in its probe of his activities while he worked at Credit Suisse First Boston. Jerome Falk, a lawyer for Quattrone, said the SEC decision "corrects the NASD's gross injustice," Reuters reported. Quattrone, a lead banker for many IPOs during the tech boom, had taken the Fifth Amendment in declining to testify before the NASD while his criminal case was pending. The SEC said the NASD was wrong in denying Quattrone an opportunity to show why he was entitled to invoke the Fifth. After one trial ended deadlocked, a federal jury in Manhattan convicted Quattrone in May 2004 on charges of obstructing a grand jury, obstructing federal regulators and witness tampering. The criminal case against Quattrone stemmed from a single email in which he recommended that his staff clean out their files and destroy documents. Quattrone and his lawyers portrayed the email as a routine Wall Street housekeeping move. But prosecutors said Quattrone had a more sinister motive, since he had just become aware of a federal investigation into CFSB's IPO practices. The trial's larger theme was CSFB's practice of dishing out hot IPO shares to favored clients and hedge funds in return for higher-than-normal commissions, or "kickbacks." But the criminal investigation of CSFB ended without any charges being brought. In 2002, CSFB settled a related civil investigation by the SEC and the NASD by paying a $100 million fine.