Is training required under §61.55 to move from PIC to SIC? I am current as PIC in type on a jet requiring two crew members. I will be out of currency as PIC soon and my company wants me to move to SIC position when that happens.

Am I required to have training specified under 14 CFR 61.55 for SIC if I am already type rated in the aircraft?
No training needed.  If you are typed in the aircraft, none of the SIC type stuff applies (that is just an ICAO formality and is superseded by having a normal type rating).  As long as you meet the requirements to act as SIC (landing currency, company training currency, etc) you are good to transition to the right seat with no additional training.