MARSEILLE, France — Marseille’s new Museum of European and Mediterranean Civilisations opened in June, part of the city’s celebration of its status as this year’s European Capital of Culture.

Though the museum is European in ambition, many of its exhibits are labeled only in French: English, though firmly established as the global language of business, education and culture, is glaringly absent from most of the signage, though an English-language audio tour is available.

A study released last week suggests that this absence is symbolic of a significant trend. The study, by Education First, an international education company, found that while English proficiency among European adults is generally increasing, proficiency in France is both low and declining.

According to the third EF English Proficiency Index, released last week, France ranked 35th among 60 nations where English is not the main language. The study put the country’s average English language skills in the “low proficiency” bracket, between China and the United Arab Emirates — and last among European nations. It also found that France was one of only two European countries where proficiency had decreased over the past six years. Norway was the other; but there, proficiency remained at such a high level that the change was insignificant.

The rankings are based on the results of 750,000 online assessment tests completed last year — some online, others by English language school applicants.

EF’s English Proficiency Index, based on the test results, compared country scores with the results of a similar study carried out between 2007 and 2009, to identify trends in proficiency levels over the past six years.

“There are some countries that are still not giving the basic message that English is a necessary skill,” said Kate Bell, a researcher with EF, in Paris.

According to Ms. Bell, the level of English proficiency among French adults suffers both from inadequate teaching at high school level and the reality that — despite fears of French culture’s being overwhelmed by American pop culture, very little English is actually used in everyday life.

Unlike its smaller northern European neighbors, France dubs most American films and television shows into French. The top English speakers in continental Europe — Norway, Sweden and the Netherlands — all tend to use subtitling.

“It’s a vicious-virtuous cycle,” said Ms. Bell: Audiences not used to subtitling tend to shy away from it, which in turn diminishes their capacity to understand English.

France’s secondary school system, which has only recently started testing English oral skills as part of the Baccalaureate, is a major reason for poor language skills, she said.

Spain, ranked at 23 in the index, has risen in the listing since introducing public English-Spanish bilingual schools. According to EF data, the country has significantly improved its proficiency level since 2007.

Eastern European countries are faring much better. Estonia is fourth in the survey, which puts it in the “very high proficiency” bracket, just after the traditional Scandinavian heavyweights. Poland, Hungary and Slovenia — all in the “high proficiency” bracket — are ranked in the top 10, with Hungary showing significant improvement.

“English is the de facto language of communication today between people who don’t share a native language,” Ms. Bell. said “Measuring English proficiency is in many ways a proxy measurement of international integration.”

Turkey, though still a “low proficiency” nation, ranked 41st in the index, was the country showing the biggest improvement in the past six years. EF researchers point to Turkey as a perfect example of economic development and international engagement that go hand-in-hand with English proficiency.

Because of its prominence in international business, higher education and politics, the importance of basic proficiency in English can scarcely be overstated. More than just a linguistic skill, adult English proficiency is key to success in the globalized world.

Conversely, the EF study suggests that weak proficiency in English may correlate with weak integration into the global economy.

“The Middle East and North Africa are the weakest regions in English,” the study said, with Iraq ranked 60th, at the bottom of the list.

“Poor English remains one of the key competitive weaknesses of Latin America,” it added, with more than half the countries in the region in the lowest proficiency band.