HARPSWELL – Selectmen have agreed to allow construction of a $350 million liquefied natural gas terminal at a former Navy fuel depot and set March 9 as the date for a town referendum on the project.

Voters will decide whether to approve a lease agreement that would allow the Fairwinds venture to use about 70 acres for a period of up to 50 years. The project, which could be completed by 2009, also needs state and federal approvals.

Harpswell stands to gain more than $380 million in revenues over the life of the lease, according to an analysis by the town.

While supporters welcomed the prospect of tax relief, others worried about the plant’s impact on the town and the local fishing industry.

“We are being asked to sell our ideals to the highest bidder,” said Ron Lapointe, a member of Fishing Families for Harpswell, which opposes the project.

“We have a chance to use this property for something that benefits all of Harpswell and for something we all could be proud of. Do we really want to be known as the town that is home to a gas plant?” he said.

Selectmen, who came out in support of the project Thursday night, said the proposed lease will be discussed Monday night at a public hearing.

“Now is the time where the hard work starts. It’s our job to help the voters understand what this lease means,” said Peter Micciche, Fairwinds’ spokesman. “I’m happy that the selectmen recognized that this was a good agreement for the town.”

The partners in the project, ConocoPhillips Co. and TransCanada Pipelines Ltd., have agreed to pay the town $8 million a year in lease fees and property tax revenues.

Fairwinds officials had hoped for a townwide vote before March 9, but Micciche said the delays should not negatively affect the project.

“The protections for the town and its residents are significantly higher than what we had at the beginning of this process,” Micciche said.

For instance, LNG tankers will be prohibited from entering or leaving Harpswell between the hours of 3 a.m. and 1 p.m. between June 1 and Sept. 30.

Fairwinds has proposed construction of a pipeline that would run under Casco Bay. The pipeline would then convey natural gas over land to an existing pipeline in Westbrook.