The companies – including ComScore-owned Nedstat – are holders of the previous contract, which expires at the end of the year.

Beginning in January 2012, the partners will begin measuring the web behaviours of a panel of 25,000 people, which is twice the size of the current panel.

The contract runs for three and a half years.

STIR managing director Frank Kok said: “A larger panel of people over the age of six years and the high frequency of reporting will increase the value and usefulness of the research for media planners and advertisers substantially.

“Data on the behaviour of the internet audience in the Netherlands is delivered weekly, but the performance of campaigns can be monitored and optimised daily.”