Credit: Lori Valigra

Maine customers buying natural gas from Unitil could be hit with a more than 9 percent increase if a rate request is approved by the Maine Public Utilities Commission.

The Hampton, New Hampshire-based utility announced the filing with the utilities commission Friday.

The request for a $7 million increase in base revenues would hike rates 9.3 percent, or $9.90 on average a month.

Unitil expects the commission to want until next year before any approved rate increase would begin.

Unitil said the goal of the rate increase is for “continued investments in the system to improve the overall safety of the system and to reliably serve a growing number of customers.”

Unitil has customers in Maine, New Hampshire and Massachusetts, with 105,600 electric customers and 82,700 natural gas customers.