From 18 months ago
http://www.themag.co.uk/2015/10/revealed-newcastles-mitrovic-and-thauvin-transfers-help-put-67m-in-pockets-of-top-agents/
So were any Newcastle players part of their dealings?
MSM are a massive presence in France and Belgium, so no surprise that they were the ones who...
According to this site both clubs have bought and sold with Marseille, over recent years, as well as a few loan deals.
http://www.transfermarkt.co.uk/newcastle-united/transfers/verein/762/plus/0?saison_id=2016&pos=&detailpos=&w_s=