The main purpose of this work is to develop a new continuous radiation scheme of medium complexity for use in atmospheric general circulation models. For this purpose the transfer equations are solved continuously from the surface up to the lower thermosphere, including deviations from the gray limit and local thermodynamic equilibrium in the long-wave regime, as well as the complete surface energy budget. Applying the new radiation scheme in a mechanistic general circulation model with prescribed concentrations of the radiatively active constituents shows quite reasonable results.