About 24 cases of corruption have resulted in judicial investigations over the last ten years, the report notes, compared to 176 in Germany and 275 in the United States.
French companies are more likely to be the subject of foreign investigations, say the authors of the report, citing Alstom in Switzerland and Technip in the USA.
Transparency also highlights the gradual but largely unreported extension of a mechanism introduced during the presidency of Jacques Chirac, under which an accused person who pleads guilty to a minor offence can negotiate a penalty with the prosecutor and avoid a public audience.
The arrangement was originally intended for use in cases involving offences such as driving while over the alcohol limit, but its use has become much more widespread in recent years.
The organisation also points to possible conflicts of interest arising from the status of the Public Prosecutor in France, who is appointed by the French president and is answerable to the Ministry of Justice.
A previous report released by the OECD in July focused on the same concern, suggesting that there the Public Prosecutor would be tempted to protect big companies in which the state is a shareholder, in the name of national economic interest.
To prevent the exercise of political pressure, Transparency International proposes that France should have an independent National Prosecutor, approved by parliament, who would have authority over other prosecutors.
The OECD in July also suggested that France should cut the link between prosecutors and the government.
During his election campaign, President François Hollande promised to introduce such a reform but has not yet done so.