Chris Brown says his criminal record played NO ROLE in why he couldn't perform at the massive Michael Jackson tribute in Wales this weekend -- claiming widespread reports that he was "banned" are simply false.

TMZ spoke with Brown's rep, who tells us Chris WAS invited to perform in the show, "however, his previously booked domestic F.A.M.E. tour concert dates didn’t allow him to accept the honor and therefore he never planned to go to the UK. He was not banned."

The rep points out that Brown spent the weekend performing in Tampa, Charlotte and Virginia Beach -- dates that had been scheduled BEFORE he was asked to join the MJ show.