Amazon.com Inc ratcheted up the pressure on Hachette Book Group by proposing the publisher's authors get all the revenue from ebooks sold by the ecommerce company, as both sides try to resolve their bitter months-long contract dispute. Hachette rejected the offer on Tuesday. The fourth-largest U.S. book publisher, owned by France's Lagardere, instead asked Amazon to immediately withdraw "sanctions" on its books. Amazon's reply to Hachette's response: "We call baloney." At the center of the highly charged dispute is the price Amazon can charge for e-books. Earlier this year, Amazon delayed delivery of some Hachette titles, including sought-after print versions and, at one point, it removed a pre-order option for "The Silkworm," by Harry Potter author J.K. Rowling writing as Robert Galbraith. Amazon, in a letter to authors and agents seen by Reuters on Tuesday, portrayed its proposal as a windfall for writers. Amazon also said it tried