The formation of hadronic atoms in multichannel systems is discussed. These atoms created in intermediate states produce different signals in the inelastic and elastic transitions. In the first case the scattering amplitude is dominated by a simple pole. In the second case an accompanying zero arises. Such structures may be quite distinct in two channel cases but disappear with the increasing number of open channels.

PACS numbers: 13.40.Ks, 14.40.--n