This is an announcement for the paper "Kreps-Yan theorem for Banach ideal spaces" by Dmitry B. Rokhlin. Abstract: Let $C$ be a closed convex cone in a Banach ideal space $X$ on a measurable space with a $\sigma$-finite measure. We prove that conditions $C\cap X_+=\{0\}$ and $C\supset -X_+$ imply the existence of a strictly positive continuous functional on $X$, whose restriction to $C$ is non-positive. Archive classification: math.FA Mathematics Subject Classification: 46E30; 46B42 Remarks: 6 pages The source file(s), RokhlinKreps-Yantheoremforbanachidealspaceseng.tex: 18929 bytes, is(are) stored in gzipped form as 0804.2075.gz with size 7kb. The corresponding postcript file has gzipped size 73kb. Submitted from: rokhlin@math.rsu.ru The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/0804.2075 or http://arXiv.org/abs/0804.2075 or by email in unzipped form by transmitting an empty message with subject line uget 0804.2075 or in gzipped form by using subject line get 0804.2075 to: math@arXiv.org.