2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/157972Let X be a Hilbert bimodule over a C*-algebra A and $O_X= A \rtimes_X \Z$. Using a finite section method we construct a sequence of completely positive contractions factoring through matrix algebras over A which act on $s_ξ s_η^*$ as Schur multipliers converging to the identity. This shows immediately that for a finitely generated X the algebra $O_X$ inherits any standard approximation property such as nuclearity, exactness, CBAP or OAP from A. We generalise this to certain general Pimsner algebras by proving semi-splitness of the Toeplitz extension under certain conditions and discuss some examples.11 pages, v2 has a modified title, abstract and introduction. The paper will appear in the Rocky Mountain Journal of MathematicsOperator AlgebrasFunctional AnalysisPrimary 46L05, Secondary 46B28On approximation properties of Pimsner algebras and crossed products by Hilbert bimodulestext