TNS, which saw off competition from Ipsos and GfK among others, will handle the business through TNS Opinion, which will co-ordinate the account across Europe.
The EU uses its Eurobarometer qualitative studies to examine reactions to different public policies or actions undertaken in connection with them.
The studies involve focus group discussions and in-depth interviews with both the general public and some specific target groups.
The business covers 34 countries and territories including the 27 member states of the European Union (EU), the three candidate countries (Turkey, Croatia and Macedonia); Norway, Iceland and Switzerland, and the Turkish Cypriot community.
TNS has worked for the European institutions since 1974 when it first won the contract for the quantitative Standard Eurobarometer studies.
Leendert de Voogd, global head of TNS Political and Social, said: "This success is due to the hard work of a large international team at TNS which successfully demonstrated our strong track record in conducting sophisticated qualitative market research globally."