A former Deutsche Bank managing director and a chartered accountant were found guilty in a London court on Monday in an insider dealing case brought by the Financial Conduct Authority.
Three other men were acquitted in the case at Southwark Crown Court, the FCA said in a statement.
Martyn Dodgson, who joined Deutsche Bank in 2008, was accused of passing information on upcoming deals to Andrew Hind, who is also a property developer, after sourcing it from investment banks where he worked. Hind acted as a middle man.
Their conspiracy on insider dealing took place between November 2006 and March 2010.
"This was an extraordinary and complex case of a type not prosecuted in this country before," Mark Steward, director of Enforcement and Market Oversight at the FCA, said.