It is shown that the effective ‘‘perturbed’’ HamiltonianHassociated with the S matrix of a system of two interacting resonances, which has one strong open reaction channel only and which is timereversal invariant, can be decomposed in a natural way into a diagonal ‘‘unperturbed’’ effective HamiltonianH0andV=H−H0. The complex energies of the ‘‘perturbed’’ system exhibit energy repulsion and width attraction as compared to the energies of the ‘‘unperturbed’’ system. This result is the direct generalization of the level repulsion theorem for the bound state case. An example in8Be is given.