Me. Rev. Stat. tit. 38, § 719

The owner of the land injured may within the time provided in section 717 offer in writing to the owner of the mill, dam or canal to accept a reduced compensation for the future. If the owner of the mill, dam or canal declines to pay it, and brings a new complaint to obtain a reduction, the owner of the mill, dam or canal may not recover costs, unless the compensation is reduced to a sum less than what was offered.