HALLOWELL, Maine — The controversial plan by Central Maine Power to build a transmission line, costing more than $950 million, from the Quebec border reached a milestone on Friday. The Public Utilities Commission wrapped up three and a half days of public hearing on the project, and will decide in the coming months whether to approve or reject the project.

Those hearings are just the first round for the power line project, which is officially called the New England Clean Energy Connect. On Friday, both sides – CMP and opponents – said the hearings helped make their case.

The NECEC project is designed to bring electricity from Hydro Quebec for customers in Massachusetts. It has created serious opposition in western Maine, where it would be built.

Opponents claim it would cut a wide, 54-mile strip through the woods and mountains of that part of Maine. They say the hearing showed that Maine would not see much benefit from the project.

But a spokesman for CMP and the NECEC says the hearing showed Mainers would see a benefit from lower electric rates.

"This project will change the energy market in New England for 20 years and it will lower energy prices for 20 years, and we are part of that market," said John Carroll of CMP. "Every Maine consumer will have the same benefit from this project as anybody in any state."

Not surprisingly, that view is not shared by project opponents.

Monica McCarthy of Say NO to the CMP Corridor says she sat through the entire hearing, and believes CMP did not give enough proof of economic benefit to Maine.

"A lot of the data that CMP used to establish what the benefits would be for Maine ratepayers was really incomplete data," McCarthy said. "Information hadn’t come from Hydro Quebec."

"Up to 70 percent of the benefits advertised for this project may not come to fruition at all," she said.

The sides disagree on many points, and it appears clear the the hearing did not change the debate. For example, there are questions by opponents whether there is a guarantee the electricity from Hydro Quebec would all come from renewable hydro. The PUC staff and attorneys for all sides will be studying that and many other questions.

A decision is expected by the PUC sometime in March, but that’s only the start. A whole round of environmental hearings with the Department of Environmental Protection is expected this spring.