C90 Controller described a loss of separation event involving a departure that had to return to the airport; the reporter sugggests better communications between the TRACON and the tower would have precluded the incident.

Narrative

I was working South Departure when the Tower got in my ear and told me that Air Carrier X needed to return to the airport. Air Carrier X checked on the frequency heading south so I turned him back to the downwind for the airport. Another Air Carrier then checked in on a southwest heading and I asked if he had Air Carrier X in sight and turned him south. I told the Vector Controller that Air Carrier X was coming back and I might put him behind an aircraft that was on the final. The Tower then put a third Air Carrier on a 220 heading and I told the West Departure Controller to stop the third carrier at 4;000 as Air Carrier X was at 5;000 crossing his path. I shipped the aircraft to the vector person. Recommendation; I should have made sure the Local Controller knew I was going to turn back to the airport. I assumed he knew since he was the person that told me Air Carrier X needed to come back to the airport. Better yet I should have just told the Local Controller to put the aircraft on the downwind and give him straight to the Final Controller.