Google Inc has unveiled a plan to help U.S. patients gain control of their medical records and is working with doctors’ groups, pharmacies and labs to help them securely share sensitive health data.

The company’s long-rumored entry into the highly sensitive field came when Chief Executive Eric Schmidt introduced Google Health at a health-care conference in Florida on Thursday.

Google said it has signed deals with hospitals and companies including medical tester Quest Diagnostics Inc, health insurer Aetna Inc, Walgreens and Walmart Stores Inc pharmacies.

The password-protected Web service stores health records on Google computers, with a medical services directory that lets users import doctors’ records, drug history and test results.

Google aims to foster sharing of information between these services, but keep control in patients’ hands, allowing them to schedule appointments or refill prescriptions, for example.