In a ruling on Tuesday, the Paris court upheld an unfair competition complaint lodged by Bottin Cartographes against Google France and its parent company Google Inc. for providing free web mapping services to some businesses.
The court ordered Google to pay €500,000 ($660,000) in damages and interest to the plaintiff and a €15,000 fine.
The French company provides the same services for a fee and claimed the Google strategy was aimed at undercutting competitors by temporarily swallowing the full cost until it gains control of the market.
"This is the end of a two-year battle, a decision without precedent," said the lawyer for Bottin Cartographes, Jean-David Scemmama.
"We proved the illegality of (Google's) strategy to remove its competitors... the court recognised the unfair and abusive character of the methods used and allocated Bottin Cartographes all it claimed. This is the first time Google has been convicted for its Google Maps application," he said.
A Google France spokesman said the company would appeal.
"We will appeal this decision. We remain convinced that a free high-quality mapping tool is beneficial for both Internet users and websites. There remains competition in this sector for us, both in France and internationally," he said.
Google has previously faced other difficulties in France and last March the country's data privacy regulator imposed a record fine of €100,000 on the company for collecting private information while compiling its Street View service.