Ed Maloney, 40, defrauded the now defunct Metronet consortium by using his firm Lakeheath Consultancy to provide contractors for underground work.
He profited from the fees his consultancy charged for placing the contractors.
British Transport Police launched an inquiry after an investigation by the London Evening Standard in 2008.
Police found Maloney was employed by a number of companies under the consortium until Metronet finally collapsed in 2007.
Maloney, of Potton, Bedfordshire, was sentenced at Blackfriars crown court on Friday after pleading guilty to fraudulent trading at an earlier hearing.
He was given a 12-month jail term, suspended for two years, ordered to do 200 hours’ community work and given a one-month curfew order.
He was also ordered to pay £10,000 costs and was disqualified from being a company director for two years.
Detective Constable Crispin Owen told the Standard: “Maloney used Lakeheath as a vehicle to defraud the companies he worked for.
“He abused his position within Metronet to bypass strict recruitment processes and award contracts to Lakeheath, profiting personally from the arrangements.”