(Reuters) - Goldman Sachs Group Inc's
Smith, a former London-based Goldman executive, condemned the powerful investment bank in a scathing New York Times opinion column in March. In British slang, muppet is a term for a stupid person.
Goldman's review found that weeks before his resignation, Smith complained about his bonus and said he deserved more remuneration, the FT reported, citing people familiar with the matter.
Two weeks after his open letter, Smith landed a book deal. "Why I Left Goldman Sachs: A Wall Street Story" will be released October 22.
Bank officials told Goldman's board of directors they could not substantiate Smith's claims and recommended no further action be taken, the FT reported.
A spokesman for Goldman did not return a call or email requesting comment.
(Reporting by Phil Wahba and Lauren Tara LaCapra; Editing by Tim Dobbyn)