The mathematical model of two firm’s competition described by the system of two differential equations with delay playing the role of capital turnover time is considered. It is shown, that the increase of capital turnover time negatively influences on stability of nontrivial equilibrium point. The maximal admissible sizes of delay at which the equilibrium point remains stable are obtained. Conditions at which restoration of stability of the equilibrium point is possible are deduced. All results are expressed directly through the coefficients of the system, which makes it possible to build a stabilizing control.