SALEM, Ore. (AP) -- The Oregon Public Utility Commission has opened an investigation to find the best solution to a looming shortage of telephone numbers in the 541 area code.

The 541 area code is expected to run out of new telephone numbers by the first quarter of 2011. The telecommunications industry has asked the Commission to approve what's called an All Services Overlay.

This means an additional area code would serve the entire 541 area. Under this plan, numbers issued after the effective date would have the new area code after all of the 541 numbers have been exhausted.

This summer the Commission staff will gather input from affected customers and make a recommendation to the Commission this fall.

The biggest possible change for residents is that upon implementation, local calls will require ten-digit dialing. Currently, local calls require just 7 digits.