Consolidated sales were up by 10.4% to €310.2m, with organic growth of 8% besting its main competitors.

Adjusted operating income “increased considerably”, the firm said – by 20% to €30.5m, while operating income was up 32.8% to €24.9m.

The custom research sector accounted for €186m-worth of sales, a rise of 11.2%. GfK said that key growth drivers were western Europe, the Middle East, Africa and Germany, however North American sales were negatively impacted by orders being shifted into subsequent quarters.

Sales in the retail and technology sector grew 13.5% to €90.4m, and the firm said that some contracts with large international customers were renewed “with considerably higher order volumes”

Media sales were down slightly to €32.6m, compared to €32.8m last year, because of lapsed contracts in western Europe, the Middle East and Africa. But GfK said that the business line improved in Central and Eastern Europe thanks to new and renewed contracts while in the US, the firm’s print media work expanded – partly as a result of the AdMeasure project that was launched last year.

CEO Klaus Wubbenhorst (pictured) said: “The first three months have shown that our growth is established on a sound and solid basis. We are confident of achieving the aims we have set for 2011.”