When you work for a group which has a parent company in a foreign country, it is worth considering learning the language of that country even if the company has designated English as the language of business. There are 3 main advantages:
– it can give you some additional insights into cultural differences
– it provides the stimulation and hopefully satisfaction of learning something which is not strictly work related
– it should give you the ability to have a converse with colleagues from the head office, even if that is confined to social rather than business topics.

The same applies if you are involved in a significant number of business transactions in another country. Naturally there is more incentive to a language if you might use it outside business as well.

Although primarily related to job seekers early in their careers, this article in Personnel Today highlights the need for us not to be too reliant on the good fortune of having English as a mother tongue!http://www.personneltoday.com/articles/2010/02/25/54404/foreign-language-skills-make-jobseekers-more-employable-during-recession.html