The Financial Services and Markets Tribunal backed the regulator's decision to issue Andrew Greystoke and his firm Atlantic Law with a ban and a fine of Â£400,000 after he gave approval to adverts issued by boiler room scam operators.
Up to 50 ads were issued by four unregulated Spanish firms between December 2005 and March 2007.
Mr Greystoke signed off the adverts despite being aware that the firmâs activities had previously attracted consumer complaints and articles in the press highlighting their âdoubtfulâ behaviour.
The FSAâs investigation found that 130 consumers had complained to the regulator after they had invested a total of Â£3 million in high-risk shares offered by the Spanish businesses through the ads.
Margaret Cole, FSA director of enforcement and financial crime, said: "Atlantic Law and Andrew Greystoke acted recklessly, without integrity and with a complete disregard of the risks to consumers.
âThe tribunalâs decision supports our view that firms and individuals that assist boiler room operators should be brought to task.â
Figures from the FSA showed that fraud surrounding stocks and shares costs the UK an estimated Â£200 million every year.
By Jim Ottewill