The help section on Ticketmaster "seems" to be clear: (but you never know with TM, could change overnight)
Can I sell Credit Card Entry tickets?
That’s up to the artist, team, or venue! If they give the green light you’ll see a Sell button when you click the order number under Order History in My Account.
If you don’t see the Sell button it’s probably because the tickets are in high demand, and the artist, team, or venue wants true fans like you to get the seats you want at face value by eliminating unfair competition from professional scalpers. Without the ability to resell tickets at steep prices, scalpers have no reason to snatch them up when they go on sale using automated software, or “bots”.
I'm in a situation where i bought 2 tickets then found 2 others that i liked better. I'm hoping that after next week (after general sale) i can sell my original 2.