create 5.1 Blu Ray in Final Cut

My question is fairly simple but for some reason I can't seem to find the answer. I have Quicktime Video (no audio) and I have a soundtrack which is 5.1 48K 24 bit WAV. I import the video and add the audio. I check the role and verify it is a 6 channel surround video. In the first case I used a 5.1 interleaved export from Pro Tools which was in this order: L C R Ls Rs LFE. This imported but when I select Share Blu Ray I see that the info window shows this as 48K Stereo. I had already confirmed that the Audio Info Inspector was recognizing this as a Surround 6 channel file. But when I burn this it is in fact stereo.

In the second scenario, I created a 5.1 from the individual tracks of the surround mix in Compressor, using the Surround Import facility that allows you to select the individual tracks. But I can not seem to get this to export as a 5.1 WAV file. When you use the WAV audio format, it converts the file to stereo. The only option appears to be ac3 which is a compressed format. I want a uncompressed 5.1 WAV file. Maybe this is not possible? I thought it was since I am planning to burn a Blu Ray.