State attorneys general and consumers have tripled the amount that they are seeking in damages from Apple after claiming that the world's most valuable technology company broke e-book antitrust rules.

According to a US court filing, the claimants are aiming to get $840m (£511m, €622m) from Apple in damages after allegedly "conclusively proving" at a trial last year that the tech group "orchestrated a conspiracy to fix prices."

Sales of e-books, launched in 2010, music, movies and software and services accounts for 8.2% of Apple's total revenue.

In 2012, sales in these products totalled $12.9bn.

US District Judge Denise Cote confirmed in the filings that the new $840m damages claim will go to court later this year.

In July 2013, Cote ruled in a non-jury trial that Apple had concocted a scheme with a group of publishers to fix prices.

Cote said 33 states were able to join the Department of Justice's lawsuit after concluding that "the publisher defendants conspired with each other to eliminate retail price competition in order to raise e-book prices, and that Apple played a central role in facilitating and executing that conspiracy."

She added that because of the conspiracy, "the prices in the nascent e-book industry shifted upward, in some cases 50% or more or an individual title."

Apple is appealing the trial judgment as well as filing an emergency request before the US Court of Appeals in New York to halt oversight by Michael Bromwich, a compliance monitor appointed by Cote.

"The monitorship the district court imposed on Apple is unprecedented, impermissible, and unconstitutional," Apple said yesterday in an appeals court filing after accusing Bromwich of taking inappropriate actions and overbilling.

"The court authorised the monitor to exercise authority that is not 'judicial'; to engage in ex parte discussions with the plaintiffs, even while the state plaintiffs are seeking hundreds of millions of dollars from Apple in another proceeding; to incur significant and unrecoverable fees that Apple is supposed to pay; and to interview anyone at Apple and demand any Apple documents."

However, Cote said in the ruling that she will not put Bromwich's work on hold as Apple failed to show how it's in the public interest although, a week later, a federal appeals court judge granted Apple a temporary reprieve from the monitor.

However, Apple will have to go through a hearing, scheduled for 4 February, so a panel of appeals court judges can hear its bid for monitor reprieve.

The lower-court case is U.S. v. Apple Inc., 12-cv-02826, U.S. District Court, Southern District of New York (Manhattan).