AUGUSTA — Maine utility regulators have approved a plan to upgrade a power line that will carry electricity produced at a windpower facility under construction near Rumford.

The Public Utilities Commission voted today to grant conditional approval to Central Maine Power to upgrade its line near Roxbury. The $13.5 million upgrade is needed to connect the proposed Record Hill wind farm to CMP’s electric transmission system.

The PUC’s conditions include a requirement that Record Hill Wind LLC make a three-month prepayment to CMP of all construction costs, and quarterly reports to the commission monitoring project progress.

Approval allows CMP to replace an existing 34.5-kilovolt line from Rumford to Roxbury with a larger 115-kilovolt transmission line.