You don't have to. Go into Bridge, select the pics you want to squeeze, click on "Photoshop," then select the Image Processor. Now you can tell Photoshop to save all the smaller versions of the shots you've selected in the same location. The squeezed shots will be saved in a new folder named "jpeg."
Next, pick JPEG as a File Type, pick a quality, and, if you want to reduce the size of the resulting pics, click Resize to Fit and choose a max pixel value for width and height. You don't need to convert to sRGB since, for some unfathomable reason you're already shooting jpeg with a camera that can produce wall-sized prints. You'll probably want to include the ICC profile. Now you're ready to click Run and save all your reduced shots.
It might take some preliminary experimentation to do this right. The only way I know of to determine what's a satisfactory JPEG quality (which actually is the reverse of jpeg compression), is to experiment with the pixel dimensions you've selected.