A decline in the number of people worldwide who speak French could cost France 120,000 jobs by 2020 and half a million by 2050, due to missed economic opportunities, a report commissioned by President François Hollande said on Tuesday.
"Unless there is a major effort, we could witness a retreat [for French speaking]," the report's author, veteran economist Jacques Attali, said in a foreword.
"This decline could lead to a loss of market share for French companies, a collapse in the use of continental law to the benefit of the Anglo-Saxon business law, and a decline in attractiveness for universities, culture and products from France and in French," he said.
Once the international language of royal courts and diplomacy, French has lost ground to English in recent decades, but the report said the right policies -- in education and industry -- could increase the number of French speakers from an estimated 230 million today to as many as 770 million by 2050.
The number could decline to fewer than 200 million by 2050 if unchecked, it said.
Hollande had asked Attali, a former adviser to President Francois Mitterrand, to find ways to harness the French language's global reach in ways that might drive economic growth, which was zero in the first half of 2014.
Economic stagnation and record unemployment are behind Hollande's decision this week to appoint his third government team in two years.
Attali's report cited research that found 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 report said.
Adding data from a further 41 nations with big French-speaking minorities, such as Israel, or with neighborly links to francophone countries, such as Nigeria, the report put the number of French speakers worldwide at about 230 million, including 130 million for whom it is their main language.