The newspaper reported Thursday its investigation indicated France's intelligence service, the General Directorate for External Security (known as the DGSE), monitored communications inside France and those made between France and abroad.
Le Monde said the prime minister's office, a parliamentary committee on intelligence and the National Commission for Controlling Security Intercepts denied the newspaper's findings.
When the latest documents leaked by U.S. National Security Agency whistle-blower Edward Snowden suggested French and European Union missions in Washington and New York had been monitored, the French government demanded it stop immediately and called for pending trade talks with the United States to be delayed until U.S. officials admitted to the extent of the covert surveillance.
The difference between the two programs is that the U.S. cellphone and Internet monitoring program included international targets while the French program was monitoring only the French, Le Monde said.
The report said some of France's politicians knew about the operation.
"A large part of the electronic communication in France is intercepted and stored by the DGSE," a political source told the newspaper.
Le Monde reported the goal was to learn who was talking to whom and identify links between "certain targets and identify certain cells."
The collected and stored data were made available to several government intelligence-related agencies, including the intelligence branch of the Paris police, the newspaper said.