The Montreal Expos obtained catcher Mark Bailey from the Houston Astros' organization Saturday in a minor-league trade for infielder Casey Candaele. Bailey hit .130 in eight games for the Astros before his demotion to Class AAA Indianapolis. He was hitting .171 in 37 games with Tucson. Candaele batted .172 for Montreal earlier this season, and was batting .264 at Class AAA Indianapolis in 60 games.