Maine’s Public Utilities Commission rejected a five-year plan proposed by Central Maine Power that would lead to a rate increase.

CMP said it wanted to invest $1 billion to improve infrastructure and bring on more workers, calling for a rate hike of as much as $35 a month on most bills.

Commission Chairman Phil Bartlett said Tuesday that all three members agree that new investments are needed, but they have to be balanced against affordability.

The commission says a rate increase is not out of the question but raised concerns about the pace of the proposed investments and impact on ratepayers.