This paper treats the non-standard two-blocks H_∞ control problem where the number of measurable outputs is not less than that of the exogenous inputs. The problem corresponds to the case where part of the system states are directly observed without measurement noise. The solvability conditions and the parameterization of the controllers to the problem are derived. It is shown that the order of the controllers can be reduced to the order of the least-order observer. As a useful application of the result, the synthesis of robust servomechanism is given.