How to package an Mac app for App Store?

Hi!

I wonder how to package my .app (Mac app) file that's produced with Flash and AIR 19 for Desktop. I try to upload the app with Application Loader to the App Store but get a message that I have to make the package for .pkg instead of .zip. Why isn't this possible with AIR compiling like with the ipa-files for IOS?

How to find a program that package for this format?

Please let me know.

Regards

Ylva Nordwall