Apple has cut deals with three more major labels to offer songs free of copy protection software on the iTunes digital music store, sources told CNET. The deal with Sony, Universal and Warner Music is expected to be discussed today at the Macworld Expo in San Francisco. In the deal, Apple has agreed to be more flexible with its pricing, dividing songs into three categories - older songs for 79 cents, midline songs (new songs that aren't topping the charts) for 99 cents and current hits priced higher. Apple has already offered songs free of digital rights management protections (DRM) from EMI for over a year, but EMI sells less than 10% of the music in the U.S. The deal will further strengthen iTunes' grasp on the digital music industry, as competitors like the Amazon, Wal-Mart and eMusic have DRM-free over a year ago but unable to overtake iTunes.