The government says it is granting four companies permission to use drones for aerial surveillance, construction site monitoring and oil rig flare stack inspections, bringing the total number of companies granted permits for commercial operations to 13.
The drones weigh less than 55 pounds and the firms have said they will they will keep the unmanned aircraft within line of sight of the operator.
Previously the only permits the Federal Aviation Administrational Aviation had issued were to two oil companies in Alaska and five aerial photography companies associated with television and film production.
The FAA said it has received 167 requests for exemptions from commercial entities.
The agency is under pressure from Congress to speed access to the U.S. skies for companies that want to operate drones.