The next Molson Brewery will not be in Montreal.

On Tuesday, Montreal Mayor Valerie Plante confirmed rumours that beer behemoth Molson Coors will establish its new brewing site in Longueuil.

"I'm disappointed. I would have like to see Molson stay on the island of Montreal," said Plante.

According to a statement issued by the City of Longueuil the new facility will be built on a parcel of land near St-Hubert Airport. The cost of the new brewery will be about $500 million. 

“We are very proud that Molson Coors chose Longueuil for this vast project,” said Longueuil Mayor Sylvie Parent. “This important gesture is rewarding years of effort to develop our city, particularly the airport zone, in order to make it a strategic part of industrial development.”

In July, the company announced that rather than renovate the 231-year-old Molson Brewery on Notre-Dame, a new facility would be opened. The proposal to sell the land to Molson Coors will need to be approved at a Longueuil city hall meeting on Dec. 5.

Plante said she had appealed to the Molson family to keep the company’s operations in the city, but an offer made by city hall had come in after the company’s board had already made its decision.

“The discussions I had with the company’s representatives confirmed Molson Coors’ and the city’s commitment to ensuring a sustainable presence for the company in Montreal,” said Plante in a statement.

“I’m confident that leaders will maintain this openness by making their next business decisions reflect not only the importance of Molson in Montreal’s history, but also the fact that Montreal helped Molson become what it is today.”

Molson isn't abandoning the city where it began its operations in 1786.

The old brewery will still be home to a microbrewery, with the rest of the property being sold for redevelopment.

"We'll continue to have a Molson legacy on the site here, where we are, and we have a lot of options right now," said Francois Lefebvre, director of corporate affairs.

Plante later said she hoped the Molson brewery site could be altered to improve housing in the area.

"We will work together to develop this huge area, it's a big opportunity for example to have better access to the water, to have better housing options maybe to develop some more," said Plante. "I'm definitely looking forward at this point and I know the Molson family wants to look at that opportunity as well."

Union president Eric Picotte is worried that the number of jobs in the Montreal area may drop as a result of the new facility.

"Molson doesn't indicate the amount of production that will be in the new site so it's a big concern for the actual employees. They don't know if it will be more or less production or if it will be in bottle or in can. So if it will be the same amount of production in can it will be a result of less jobs for the new site," said Picotte.

Molson hopes to begin construction of the new factory in early 2018, and finish the job by 2021.

With files from Angela MacKenzie