• by Joe Mandese  @mp_joemandese, February 17, 2012

Paris-based Publicis Groupe this morning said it bought back 18 million of its own shares from Tokyo-based Dentsu, marking an end to a 10-year strategic equity relationship between the two agency holding companies that began when Publicis acquired Bcom3 -- which Dentsu owned a minority stake in -- in 2002.

The companies said Dentsu will continue to hold a 2.12% stake in Publicis.

The cash purchase, which was valued at about $850 million, was completed this morning, and senior Dentsu executives have resigned from Publicis’ board.

“The friendly relationship and collaboration between the two groups will continue,” the companies stated.

In addition to Dentsu’s continuing minority stake in Publicis, the companies said they would continue to operate two joint ventures, with their original equity shareholdings: Beacon Communications and Dentsu Razorfish, owned respectively 66% and 19.35% by Publicis Groupe.

“Moreover, partnerships related to specific clients that the two groups have in common will continue, in the clients' interests,” the companies said.