The news comes nearly three years after Mercedes parent Daimler and the Renault Nissan alliance announced a strategic technology sharing and development partnership in 2010.
The Q50, Infiniti's replacement for the current G sedan, was revealed last month in Detroit, debuting with Nissan's 245kW 3.7 litre petrol V6 and a 270kW 3.5 litre petrol-electric hybrid system.
Details of the new Mercedes-sourced engines have not been revealed, although it is known that smaller-capacity turbocharged petrol and diesel options are bound for the Q50 range.
“The Infiniti Q50 is a world-class sports saloon with an engine line-up that will clearly demonstrate its intentions to be a major player within the European premium market," Infiniti's Bernard Loire said.
The carmaker is expected to reveal more information on the new engines in early March.