Riviere as well as sporting director Julien Fournier will sell their remaining 20pc stake in the outfit coached by World Cup winner Patrick Vieira and the pair will stand down in May.
"It's an open secret that we have had our differences with our owners and these tensions have intensified during the transfer window," Riviere said in a press conference.
Hong-Kong-based OGC Nice Investment Company Ltd founded by Chinese-American Chien Lee, Chinese Alex Zheng and American Paul Conway originally bought it's 80pc share in June 2016.
Riviere and Fournier oversaw a succesful period both on and off the field for the club since arriving in 2011.
They helped the side to reach the Champions League qualifying stages for the first time in its history and sold players like Jean-Michel Serri, Alassane Plea and Brazilian Dalbert for a combined price of 75 million euros ($86mn).
The Chinese-American consortium join Qataris at Paris Saint-Germain, Russians at Monaco as well as Americans at Marseille and Bordeaux as foreign majority owners of sides in France's top-flight.