DRM is class of access control technologies used by copyright holders to limit the distribution of digital content. Publishers use DRM to protect their e-books from piracy, but it is unpopular among many customers because it prevents them from sharing titles between electronic devices.

Tor UK, whose parent company Macmillan is currently embroiled in a US lawsuit over accusations of e-book price fixing, said that the decision to ditch DRM was made alongside similar moves by its US partners, including Tor Books and Forge.

"We know that this is what many Tor authors passionately want," said Jeremy Trevathan, Pan Macmillan's fiction publisher. "We also understand that readers in this community feel strongly about this."

Tom Doherty, president and publisher of Tom Doherty Associates in the US - which publishes Tor, Forge, Orb, Starscape, and Tor Teen - added that authors and readers are "a technically sophisticated bunch", and DRM is a constant annoyance to them.

"It prevents them from using legitimately-purchased e-books in perfectly legal ways, like moving them from one kind of e-reader to another," he said.