\documentclass[12pt]{article}
\usepackage{soul}

\begin{document}

foo\ldots{} bar

\hl{foo\ldots{} bar}

foo\ldots\ bar

\hl{foo\ldots\ bar}

\end{document}

% $Id: soul-space.tex 17309 2007-05-11 14:21:40Z lefevre $