Mobile applications seeking to collect personal information will have to forewarn users as part of an agreement reached in California.

The guidelines announced Wednesday by California Attorney General Kamala Harris are designed to protect consumers who don't realize that some applications are pulling potentially sensitive data from their smartphones and computer tablets.

Harris says mobile apps that will keep users' personal information will have to spell out their intentions in privacy policies that potential users must see before the apps can be installed on a device.

Six of the mobile computing market's most powerful companies have agreed to set up ways to post the privacy policies in online app stores. The cooperating companies are Google, Apple, Amazon.com Microsoft, Hewlett-Packard and BlackBerry maker Research in Motion Ltd.