The number of French speakers across the world grew 25 percent since 2010, the International Organisation of La Francophonie (OIF) said in a report published on Wednesday, a potential boost as France seeks growth from overseas opportunities.

Once the international language of royal courts and diplomacy, French has lost ground to English in recent decades, but experts say the right policies could harness the French language's global reach in ways that might drive economic growth.

But according to the OIF, the number of French speakers increased from about 220 million in 2010 to 274 million in 2014, making it the fifth most widely spoken language in the world.

"French is benefiting from the demographic growth of sub-Saharan African nations," the OIF's outgoing secretary general Abdou Diouf said.

Economic stagnation and record unemployment has pushed President Francois Hollande to new areas to help revive growth.

Foreign Minister Laurent Fabius was handed the task of reducing the trade deficit and developing external business as part of an expanded portfolio to boost those growth opportunities overseas earlier this year.

Since taking the foreign ministry post in 2012, he has tried to shift Frances's diplomatic focus more towards winning contracts in markets where French firms are traditionally weak, and to refocus Paris' influence on the African continent to compete more aggressively with new players like China.

A separate report commissioned by Hollande found in August that countries with linguistic connections do 65 percent more business with each other than those that do not.

There are 37 'francophone' countries where French is either an official language or is spoken by at least one in five of the population - making it an "enormous and insufficiently exploited" economic resource, the August report said.