Livent co-founders Garth Drabinsky and Myron Gottlieb were both convicted in 2009 of two counts of fraud and one count of forgery.
Judge Mary Lou Benotto found both men manipulated Livent’s statements over nine years to attract investors, before the company went bankrupt in 1998.
The Tony award-winning producers claimed their accounting staff perpetrated the fraud without their knowledge.
The Ontario Court of Appeal rejected their efforts to appeal the convictions on Tuesday, but agreed to trim two years from their sentences.
Drabinsky must now serve five years, and Gottlieb four.