The UK's education system is failing to produce enough people with foreign-language skills to meet a growing need from business, the CBI has said.
Nearly two-thirds of about 300 UK firms surveyed by the business lobby group said they preferred staff with these skills.
French, German and Spanish were highly prized but Arabic and Mandarin were growing in importance, it said.
The government said its policies meant more children were learning languages.
The report refers to British Council research citing an "alarming shortage" of speakers of certain major languages.
The CBI/Pearson Education and Skills Survey suggested languages were likely to continue to grow in importance "as ambitious firms look to break into new, fast-growing markets".
Some 41% of businesses said knowledge of a foreign language was beneficial, while 28% believed language skills would help to build relations with overseas contacts.
French (50%), German (49%) and Spanish (44%) were identified as the most useful languages.
A total of 31% wanted staff who could speak Mandarin and 23% demanded Arabic skills.
Others identified Polish (19%), Russian (18%), Cantonese (16%) and Japanese (15%).
CBI deputy director general Katja Hall said research showed one in five schools in England had a persistently low take-up of languages.
She said: "With the EU still our largest export market, it's no surprise to see German, French and Spanish language skills so highly prized by companies.
"But with China and Latin America seeing solid growth, ambitious firms want the language skills that can smooth the path into new markets," she added.
"It has been a worry to see foreign-language study in our schools under pressure.
"The jury remains out as to whether recent government initiatives can help spur a resurgence in language learning.
"Young people considering their future subject choices should be made more aware of the benefits to their careers that can come from studying a foreign language."
Last year a report by the British Council urged schools to teach a wider range of languages, giving these skills the same status as the sciences and maths.
"In a tight economy, one thing that will help more UK young people choose languages is a clear signal from UK businesses that they want them and will pay for them," said John Worne, the organisation's director of strategy.
"Money talks, but it's people being able to communicate that makes the world go round."
A Department for Education spokeswoman said the proportion of teenagers taking a language GCSE fell from 75% in 2002 to 43% in 2010, but exam changes have meant the figure rose to 49% last year.
"This government is overseeing a languages revival after a decade of damaging decline," she said.
"From this September, languages will be compulsory from the age of seven, rather than 11 at the moment.
"And our EBacc has seen the numbers learning languages at GCSE rising again after many years of consistent decline."