[NEW YORK] Dow Jones & Co Inc, publisher of the Wall Street Journal, has asked a court to deny a request by Apple Inc and GT Advanced Technology Inc to keep under seal some documents relating to GT Advanced's bankruptcy.

Dow Jones, owned by News Corp, said keeping the documents under seal is an offense to constitutional principles of public access, according to the publisher's court filing on Tuesday.

GT Advanced, which supplied sapphire material to Apple to make smartphone screens, filed for Chapter 11 protection earlier this month and refused to explain why it had imploded, citing confidentiality clauses in its Apple contracts.

Few details have emerged since the bankruptcy filing, which wiped out most of GT's market value and triggered speculation over what may have soured its relationship with Apple.

Dow Jones said in Tuesday's filing that the companies' had not cited any authority to support their "brazen" request and asked the court to reject their "ransom" demands.

Under US bankruptcy laws, there are narrow exceptions which allow documents to be sealed and Dow Jones said neither company had argued that certain documents in the case qualified for this extraordinary protection. "To the contrary, GTAT has stated unequivocally that the sealed materials do not satisfy the statutory test," Dow Jones said in the filing.

GT Advanced and Apple were not immediately available for comment.

GT Advanced, which proceeded with its bankruptcy after striking an agreement with Apple, said earlier this week that the iPhone maker had threatened to seek damages of more than US$1 billion against the company.

The case is In re: GT Advanced Technologies Inc, US Bankruptcy Court, District of New Hampshire, No: 14-11916.

REUTERS