2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/62623It is proved recently by Benamara-Nikolski that a contraction having finite defects and spectrum not filling in the closed unit disc, is similar to a normal operator if and only if it has the so-called linear resolvent growth property. We obtain results of the same type for a wider (than contractions) class of operators.LaTex, 17 pages, preliminary versionSpectral TheoryClassical Analysis and ODEs47B15, 47B44text