The successful tender is expected to initially include page impressions, unique browsers and unique devices, with a view to include audience measurement and viewable impressions at a later stage.

The announcement signals a shift from its current web audit service, which was based on an exclusive partnership with Nielsen, and the AMAA will now look to partner for each of the metrics which will be audited and reported through its eData Portal.

The AMAA said the move to introduce new metrics followed “considerable member consultation” which identified the need to report multi-platform activity by device as a key objective.

In particular, the association wanted to explore the introduction of a unique device metric, which will record the number of unique devices that have generated a tagged item of content over a variable time period.

“The potential to deliver a reliable monthly unique device figure is looming as critical for smaller specialist and niche publishers who no longer have access to a monthly unique browser or unique audience metric,” said AMAA CEO Paul Dovas.

Web measurement technology providers are invited to submit proposals by 24 May 2013 with submissions to be assessed by a review committee.