Reed has a .153 career average over 48 games for Houston from 2016-18. He had spent this season at Triple-A Round Rock and was designated for assignment by the Astros on July 2.
The White Sox also transferred right-hander Ryan Burr to the 60-day injured list. He has been sidelined since late May and had Tommy John surgery on his pitching elbow on June 25.
Burr was 1-1 with a 4.58 ERA in 16 games -- one start -- this season.