Open your audio project you have created in Cubase Le. Mute all tracks except for the audio track you wish to transfer. Each track has a mute/unmute button that is denoted by a horn symbol.
Select "Export" from the "File" menu heading. Select "Audio Mixdown" from the pop-up menu that appears.
Name the audio file you are exporting. Give the file an easily identifiable name and save location.
Select "Wave file (.wav)" from the "Files of type" drop down menu. Click the "Save" button.
Open a new project in Pro Tools once the file has completed saving. Under Pro Tool's "File" heading select "Import." In the window the appears in the middle of your screen, navigate through your computer and select the saved audio file you created. Click "OK." The file will appear in a new track of your Pro Tools project.