Method of operating an internal combustion engine

A method of operating an internal combustion engine having a cylinder, a cylinder head including inlet and outlet valves, a piston movably disposed in the cylinder and defining a combustion chamber between the cylinder head and the piston to which fresh air is fed via an intake manifold, said method comprising the steps of:

• operating the internal combustion engine selectively in a compression ignition or in a spark ignition mode depending on the engine operating point, wherein, in a compression ignition mode,
• exhaust gas is retained in the combustion chamber and compressed during a charge change, and
• a first fuel quantity is injected into the retained exhaust gas by means of a first fuel injector arranged in the combustion chamber so that a homogeneous gas/air mixture is formed in the combustion chamber, and
• supplying a second fuel quantity subsequently to the combustion chamber by means of a second injector arranged in the intake manifold, so as to form a homogeneous fuel/gas/air mixture in the combustion chamber.