Facebook Inc. is developing technology that would allow children younger than 13 years old to use the social-networking site under parental supervision, a step that could help the company tap a new pool of users for revenue but also inflame privacy concerns.

Mechanisms being tested include connecting children's accounts to their parents' and controls that would allow parents to decide whom their kids can "friend" and what applications they can use, people who have spoken with Facebook executives about the technology said....