Skyhawk 172/Cutlass 172
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 8
Time Pressure; Situational Awareness; Confusion; Communication Breakdown; Training / Qualification
ATC Issue All Types; Conflict NMAC
Airspace Structure; Human Factors
Aircraft X released off LGB airport by Manhattan/Laker combined sector; training in progress.  I was working the Controller in Charge position; when the trainer working position advised me of a possible situation in progress.  I observed the trainee/trainer issuing a safety/traffic alert to the departing IFR aircraft and observed opposite direction traffic at co-altitude.  Once the situation had been resolved I felt the situation appeared to be a near midair collision and was unaware of traffic being issued by the tower.  I contacted LGB Tower to figure out if they had issued traffic and were doing anything to ensure separation.  The LGB Controller didn't seem to be aware there was even a situation and didn't seem to care that we and pilots in control of both aircraft had to take evasive action; after further communication with the departing aircraft we determined no traffic was issued to the IFR aircraft prior to transfer of communication despite the unsafe situation.  I have still not been made aware of any traffic issued to the other aircraft that LGB Tower was in communication with but it did appear that aircraft also took evasive action and turned hard south to avoid collision while our departing IFR aircraft turned north west.LGB Tower Control needs to maintain communication with both aircraft and issue and resolve any conflicts prior to transferring communications.  I feel the Tower Controller needs immediate remedial training and be explained duty priority; then be able to demonstrate this ability before being returned to active duty.
SCT TRACON Controller reported an unsafe situation with traffic off of LGB and traffic inbound to LGB.