The envelopes were opened Wednesday and the winner in the contractor’s bidding contest for the right to construct the expansion of the University of Maine’s Alfond Arena is…. Granger Northern Inc., of Portland.

Richard Eustis, UM Vice Chancellor for Facilities, pronounced Granger Northern the lowest bidder at $2,817,000. The Portland-based company’s bid narrowly edged the Lawlor Corp. of Massachusetts, by $17,500.

A total of four bids were submitted for the project, which calls for the roof of the Alfond Arena to be raised, two walls to be pushed back, with extra seating and sky boxes to be added. The changes will enable seating capacity for hockey games to be increased from 3,800 to 5,200. The expanded facility will seat 6,000 for basketball.

“We’re very pleased with the bid, with all the bids,” said Eustis. “They were less than the architect had estimated the cost would be.”

The total budget for the project is approximately $3.9 million.

Despite the fact the project is two months behind the original schedule, Eustis said he believes the facility can be useable in time for hockey season.

“The contract requires the roof be removed and replaced and the existing seating capacity be available for the start of hockey season Nov. 1,” Eustis said. “There will be work going on, and additional seating will not be available until after the first of the year. We don’t think the sky boxes will be ready for hockey season. We won’t know that until we sit down with the contractor.”

Eustis said a meeting had been set with the contractor next Tuesday morning. The ground-breaking should follow soon after.

“I would expect the contractor will have a crew on site within 10 days to two weeks,” Eustis said.

The other bidders were Sheridan Corp. of Portland and Downeast Associates of Bangor.