Semi-invertible extensions of C∗-algebras

We prolong the list of C∗-algebras which have the property that all extensions by a stable C∗-algebra are semi-invertible. In particular, it is shown to include group C∗-algebras, both reduced and full, of certain amalgamated free products of amenable groups, as well as all free products of nuclear C∗-algebras with amalgamation over a common nuclear C∗-subalgebra. © 2010 Elsevier Inc. All rights reserved.