Salomon Smith Barney, Citigroup's investment banking unit, has been fined $5m (€5m) after regulators found that Jack Grubman, the bank's former star analyst, misled investors about a failed telecom company.

NASD, formerly the National Association of Securities Dealers, censured and fined SSB after uncovering evidence that Grubman and a colleague hyped up Winstar in research reports while privately they held reservations about the company.