The 32-year-old stated his desire to leave after not being given a chance this season and has joined former City hopeful Andy Smith at Aberdeen side Culter.
Pirie said: "David Robertson had a pop at me in the press last week because I said I wanted to leave. We disagreed on one or two things, so it was best for me to move on and I'm glad that has now happened.
"I spoke to Elgin chairman Denis Miller last week about moving on when I heard Culter were interested in me. I phoned the chairman on Friday to thank him for letting me go because it was the best thing for both parties."