A former Massachusetts Institute of Technology associate dean and his son have been sentenced to 3¾ years in prison for a hedge fund scam that cost investors more than $140 million.

Federal prosecutors say 70-year-old Gabriel Bitran and 40-year-old Marco Bitran were also ordered Monday to pay more than $11 million in restitution.

The two pleaded guilty to securities fraud, wire fraud and obstruction of justice last year in connection with their hedge fund businesses, GMB Capital Management and GMB Capital Partners.

Prosecutors say the men claimed they could produce annual returns of 16 percent to 23 percent based on the elder Bitran's investment theories.

But authorities say some of the $500 million invested with them was put into Bernard Madoff-connected funds. They ended up costing some investors as much as 75 percent of their principal.