The publisher, owned by Pearson, said it will experiment selling its audio books without digital rights management software, which would allow readers to play them on any digital device.
Readers will be able to download the audiobooks in MP3 format on US site , which is the web's second-largest digital music service after iTunes.
Around 250 titles are to be made available, including: Michael Pollan's 'In Defence of Food'; Elizabeth Gilbert's 'Eat, Pray, Love'; and Eckhart Tolle's 'A New Earth: Awakening to Your Life's Purpose', which was picked by Oprah Winfrey for her book club.
Marjorie Scardino, chief executive of Pearson, said: "I don't think we can be worried about every incursion from electronic selling and electronic use. We have got to think about what the future is going to be and look at how to experiment with it."
The move follows similar action by Random House, which announced last month that it would start selling its audiobooks as unprotected MP3 files from March 1, unless retail partners or authors specified otherwise.
Yesterday, Pearson revealed a 4% rise in statutory pre-tax profits to £468m for the year ending December 31.
Penguin's adjusted operating profit was up 20% on 2006 to £74m thanks to increased sales in titles including Kim Edwards' first novel, 'The Memory Keeper's Daughter', which was a number one bestseller for Penguin in the US, UK, Australia and Canada.