France possesses 40% of the 25,000,000 square kilometers in question, i.e., 10,000,000 square kilometers
75% confidence
EnvironmentFrance
Omissions
The MEP did not specify that this refers to the EU's Exclusive Economic Zone (EEZ), not global maritime territories.
France's EEZ is actually reported as 10.2-10.7 million km² depending on the source, slightly higher than the 10 million stated.
The total EU EEZ area appears to be approximately 25 million km², though exact official figures from Eurostat for this specific metric were not found in the search results.
Sources found were secondary (Wikipedia, Reddit citing other sources) rather than primary official maritime databases.
Sources
SecondaryIslands Business (Facebook)France manages a vast Exclusive Economic Zone (EEZ) covering nearly 10 million sq km in the Pacific.
TertiaryGrokipediaFrance's EEZ spans approximately 10.7 million square kilometers, ranking as the second largest globally after the United States.
TertiaryReddit r/MapPornFrance has 10.2 million km² of EEZ. The United States has the largest EEZ at 11.3 million km².