Amazon, Apple, Google, Microsoft, RIM and HP have signed an accord to provide greater privacy disclosures to users before they download mobile apps, reports Reuters.

The idea of the agreement made in California is to protect the personal data of consumers by disclosing how it will be used, according to state’s attorney general Kamala D. Harris. The agreement also encompasses developers building apps on the platforms used by the companies.

Under the agreement, Google said Android users will be able to make more informed decisions when it comes to privacy. Apple confirmed to Reuters that it had signed the agreement.

Harris said 22 of the 30 most-downloaded apps do not have privacy notices, with some even downloading the contact books of mobile users without warning. "Your personal privacy should not be the cost of using mobile apps, but all too often it is," she said. California’s 2004 Online Privacy Protection Act requires privacy disclosures but there has been confusion about whether this related to mobile apps, according to Harris.

The six companies will meet with the attorney general in six months to discuss how their developers are complying with the rules. If developers fail to adhere to the privacy rules litigation could take place, Harris added.

Harris was among the 36 US lawmakers who signed a letter to Google CEO Larry Page expressing serious concerns about Google’s recent decision to consolidate its privacy policy. The policy would give Google access to user information across products including Gmail and Google+, without providing the proper ability for consumers to opt out. European authorities have asked Google to halt the policy change until its implications have been investigated.