Alcoa’s massive aluminum-smelting plant near Goose Creek and state-owned utility Santee Cooper have agreed to extend the power contract deadline until Dec. 31, both entities announced Thursday.

The two parties have been working on a power rate for several years that would allow Alcoa to remain profitable at its Mount Holly plant and Santee Cooper to provide power at an economical rate.

The deadline requires Alcoa to notify the power provider if the current contract, which expires in December 2015, will be renewed.

The extension also allows Alcoa and Santee Cooper to continue talks on a post-2015 power contract.