1. Click on Share and then Export using Quicktime.
2. Enter a name for your movie file.
3. Select where you want to save your exported Quicktime movie to.
4. In the Export field choose Movie to Quicktime Movie.
5. Click on Options
6. Under video click on Settings:
Compression Type: H.264
Frame Rate: 24 fps
Key Frames: Every 24 Frames
7. Click OK
8. Click OK
9. Click Save. Your iMovie will export to a Quicktime movie.