An American judge who found technology firm Apple liable for conspiring to fix e-book prices imposed injunction on the iPad makers to prevent it from breaking further rules.
A court ruled in July that Apple was guilty of entering into an agreement with five major American publishers to control e-book prices.
District Judge Denise Cote in Manhattan said Apple could not make such agreements and appointed an external monitor to work with the business to ensure it sticks to the rules.
The terms of the judgment will expire after five years, but Cote's order allows for extensions in one-year increments if necessary.
The injunction followed a 10 July ruling by Cote which found that Apple conspired with five publishers to undermine e-book pricing established by the dominant retailer in the market, Amazon.com Inc.
The five publishers, all of which have settled with regulators, include Lagardere SCA's Hachette Book Group Inc, News Corp's HarperCollins Publishers LLC, Penguin Random House LLC, CBS Corp's Simon & Schuster Inc and Verlagsgruppe Georg von Holtzbrinck GmbH's Macmillan.
The US Justice Department, which sued Apple in April 2012, had initially sought an even broader injunction that could have touched on the company's agreements with suppliers of other types of content, such as movies, music and TV shows.
But Cote had made clear at a hearing last week that she would not go that far, saying she wanted the injunction "to rest as lightly as possible on how Apple runs its business."
The Justice Department said it welcomed the injunction.
"Consumers will continue to benefit from lower e-books prices as a result of the department's enforcement action to restore competition in this important industry," Assistant Attorney General Bill Baer said in a statement.
Apple said today that it would appeal the injunction.
"Apple did not conspire to fix e-book pricing," said company spokesman Tom Neumayr. "The iBookstore gave customers more choice and injected much-needed innovation and competition into the market."