Hodder & Stoughton is to purchase Quercus.
The announcement was made to the markets today by the boards of Hachette UK, Hodder's parent company, and Quercus.
The purchase amount is around £12.6m.
Under the terms of the offer, Quercus shareholders will be entitled to receive 60p per Quercus share.
The offer is now subject to conditions, with the deal due to be completed in early May.
Tim Hely Hutchinson, c.e.o. of Hachette UK and chairman of Hodder, said: "My colleagues at Hodder and I greatly admire what has been achieved at Quercus in a relatively short time. If our offer is successful, Quercus will become a distinct division within our company and will benefit from Hachette UK Group's funding resources and sales reach to secure a very bright future for the Quercus Group."
Mark Smith, chief executive of Quercus, said: "Over the last 10 years we have built Quercus into a £20m+ revenue business, with divisions in both the UK and North America. During this time we have helped debut authors become established bestselling brand names, published the international phenomenon that is the Millennium Trilogy and have built what we believe to be a world class roster of authors from across the globe. For the next phase of its development and to fulfil Quercus' potential, we believe that Hodder and Hachette UK is the right home for Quercus."
David Potter, chairman of Quercus, said: "In today's highly competitive and technological world, Quercus' board believes that publishers will best fulfil their potential by being part of a larger and more diverse group. We believe that Hodder is the right home for Quercus and in particular our publishers and authors, who remain the lifeblood of our business."
Agent Carole Blake told The Bookseller that she was “not entirely surprised" by the purchase. "I think a lot of people thought Hachette were in the running but Hodder weren’t mentioned, it was usually Orion," she commented. She added that the news was "as good as can be expected", noting: "Hachette is generally seen as a benevolent purchaser, although recent news about Constable and Robinson’s redundancies does make you worry.”