Two US lawmakers have asked Google chief Larry Page to brief congress on changes to the Internet search giant's privacy policies, citing concerns about collection and sharing of personal data.

Republican Representative Mary Bono Mack and Democratic Representative G.K. Butterfield, the top members of the House Subcommittee on Commerce, Manufacturing and Trade made the request in a letter to Page on Friday.

"We applaud the move toward a shorter, simpler, streamlined policy, and believe that easier-to-understand terms of service are in the best interest of consumers," they wrote.

"We are concerned, however, with other changes to Google's privacy policy, particularly with how a user's data will be collected, combined, archived, and used across services," they said in the letter, which was released Monday.

"These changes might not otherwise be troubling but for one significant change to your terms of service: Google will not permit users to opt out of this information collection and sharing across platforms and devices," they said.

The lawmakers asked Page or his "designee" to brief the subcommittee no later than Friday.