mixing AS2 and AS#

So currently my game company is using AS2. We have a shell.swf that loads in all of our games. The shell is written in AS2 like all of our other stuff. Some of our games we have contracted others to make. Those other people are converting to AS3. Can our AS2 shell still be able to load AS3 swfs? Or does EVERYTHING have ot be in AS3 or AS2 for it to work?

Thanks!
Kyle