MediaCom is disputing new RECMA figures after the research company revised its media billings overnight relegating the agency from top spot to third, adding an extra $378m to Mitchell & Partners.

The GroupM agency had been told in July they had knocked long-term incumbent Mitchells from the top spot in the standings, only to find out last night they had been dropped to third, with OMD also sitting on top of the pile after a revision of how the data was compiled.

Mark Pejic, CEO of MediaCom, told B&T this morning: “We’re surprised by the new methodology and we're in discussion.”

Today the NSW Government revealed it has dropped MediaCom from its main media account in favour of UM.

One source said the way RECMA had recalculated the figures was "kinder to the longtail, and Mitchells has a famously long tail", with the revision coming after Nielsen failed to produce its annual billings report this year.

The revised figures, based on a methodology the researchers use in other countries, takes into account clients spending under $1m, something not done by Nielsen, although this has led some to question the accuracy of the new figures. 

The restated numbers puts Aegis-owned Mitchells on top of the pile for the ninth year in succession with their overall billings soaring from $887m in the July figures to $1.265bn in the new methodology.

Other Aegis agencies Vizeum and Carat dropped $45m and $30m respectively in the new metrics.

In a statement Luke Littlefield, CEO Aegis Media Australia & New Zealand said: “We are pleased to be reinstated as number one agency for the ninth year running.  

"We are equally happy to see our other agencies, Carat and Vizeum ranking well.  It is testament to the work we do and the path that we’re on as a business. We appreciate the support of our clients and staff in this achievement.”

However, the new numbers also knock off $33m from the overall billings for MediaCom, taking the agency from $1.215bn in July to $1.182bn,  while OMD moved from second to joint-top with $1.262m, a $61m rise.

In the report in July MediaCom was accredited billings of $1.215bn, a 20% uplift on last year, while Mitchells was credited with an 11% decline to $887m, and OMD saw a 5% lift to $1.144bn.

UM is fourth overall gaining $36m up to $852m, although those figures also include billings from IPG Mediabrands' third-tier agency MBThree, which holds the Coles media account, and was officially merged with UM Melbourne yesterday.