A US judge has placed regulations on the agreements Apple can make with book publishers in an attempt to block the price of e-books being fixed.
The imposed restriction follows a court ruling in July that Apple was guilty of leading a conspiracy to fix the price of e-books with five publishers.
This time round, the judge has said Apple must hire an external auditor to ensure it follows the new rules.
Penguin, Macmillan, Hachette, HarperCollins and Simon & Schuster were accused of price fixing alongside Apple, but unlike the tech firm, all settled out of court.
The initial legal action was launched The US Department of Justice, after it said the firm had embarked on the price fixing scandal in an attempt to challenge Amazon's dominance of the e-book market.
"We're pleased that the court has issued an order supporting the Department of Justice's efforts to address Apple's illegal price fixing conduct," said assistant attorney general Bill Baer in a statement.
Apple is now banned from entering any agreement that could lead to prices being fixed. The ruling will be enforced for five years, after which a judge can order an extension.
"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," added Baer.
"By appointing an external monitor to ensure future compliance with the antitrust laws, the court has helped protect consumers from further misconduct by Apple."
Apple continues to say that the allegations are false.