Abstract. The following result uses and generalizes a recent result of Ayache on integrally closed domains. Let R be a commutative integral domain with integral closure R (inside the quotient field K of R) such that each overring of R (inside K) is a treed domain and there exists a finite maximal chain of rings going from R to R . Then R is a seminormal domain if and only if, for each maximal ideal M of R, either R M is a pseudo-valuation domain or, for some positive integer n, there exists a finite maximal chain, of length n, of rings from R M to (R M ) each step of which is (an integral minimal ring extension which is) either decomposed or inert. Examples are given in which the latter option holds where R is one-dimensional and Noetherian.Mathematics Subject Classification (2010): Primary 13B99, 13G05; Secondary 13F05, 13B21, 13E10