Stephen Whiteley, 65, from Beverley, East Yorkshire, was part of a conspiracy to pay out bribes totalling six million US dollars (£4.9 million) to politicians and state-owned companies after Saddam Hussein was toppled in 2003.
Executives at the Monaco-based oil company Unaoil hoped to secure Iraqi contracts worth 800 million US dollars (£650.7 million) as the new government tried to rebuild the country in the aftermath of the war.
Whiteley was convicted of one count of conspiracy to make corrupt payments alongside Ziad Akle, 45.
Addressing Whiteley, who appeared via videolink at Southwark Crown Court on Thursday, Judge Martin Beddoe said: "I acknowledge that you played a subordinate role to that of Akle."
He added: "There's only one way with dealing with you today, it's a way I'm sure you have known for a long time."
Whiteley was sentenced to three years in prison.
On July 23, Akle was sentenced to five years in prison after he was found guilty of two counts of conspiracy to make corrupt payments.
Akle, from Marylebone, London, who is a British-Lebanese national, was Unaoil's territory manager for Iraq and Whiteley was vice president of Dutch-based company SBM Offshore until May 2009 when he joined Unaoil.