David Chacon, the former Salomon Smith Barney (SSB) banker who alleged that his previous employer favourably gave shares in 'hot' initial public offerings to telecoms executives, has resigned from his current employer, Credit Suisse First Boston (CSFB).

SSB fired Chacon in May 2000 and last month he filed a lawsuit alleging that the bank targeted executives from whom it was trying to win investment banking business, including Bernie Ebbers, the former head of Worldcom. Chacon claimed SSB gave shares of internet stocks in IPOs to executives at issue price after the shares rose in early trading based on recommendations from Jack Grubman, SSB's star telecoms analyst.