Penguin Random House (PRH) and are reported to be involved in a terms dispute, which may raise fears that Amazon will limit the availability of PRH titles.

Amazon's terms with the five leading U.K. publishers have come up for renewal this year, and an Amazon UK spokesman told BookBrunch that PRH was the last of them to settle. "I can't comment on that rumour," he said of the reported dispute with PRH. "I can say that we have long term deals in place already with the other four major publishers and we would accept any similar deal with Penguin Random House UK."

A PRH spokesman played down the prospect of punitive action at "We are in continuous conversation with Amazon with whom we have an ongoing business relationship. We have no intention whatsoever of ceasing to sell our print or digital titles on Amazon. We want our books to be accessible and available everywhere."

Similar disputes in the past have led to Amazon's withdrawal of buy buttons from publishers' titles, as well as the delaying of shipments. Last year, the online retailer took these measures against Hachette Book Group USA, denting the publisher's e-book sales in particular. But PRH may hope that its market share - it has more than 23% of the Nielsen Total Consumer Market in he U.K., according to the Bookseller - may give it a more powerful negotiating hand. It had five of the six titles on the Man Booker shortlist, and at the time of writing is responsible for four of Amazon's top 10 bestsellers.

In the U.S., Penguin but not Random House was part of the antitrust case bought against Apple and five publishers over the introduction of the e-book agency model, under which publishers imposed prices and retailers received set commissions. With the Penguin-Random House merger, PRH became subject to the DoJ terms. New agreements between Amazon and U.S. publishers involve versions of this model that retain publishers' pricing control, but with incentives to make prices lower. Similar to the U.K., PRH is the last of the Big Five American trade houses to negotiate new terms with Amazon. Leading U.K. publishers are also dealing with Amazon under revised agency terms, following a European Commission ruling against their previous arrangements. These terms, negotiated at the end of 2012 and start of 2013, were for two-year periods.

This article is based on reporting the first appeared in the U.K. newsletter BookBrunch.