With more than $7 billion in assets,Gaz Métro is a leading energy provider. It is the largest natural gas distribution company in Quebec, where its network of over 10,000 kilometres (6,200 mi) of underground pipelines serves some 300 municipalities and more than 200,000 customers. Gaz Métro is also present in Vermont in the United States, where it has more than 310,000 customers through its subsidiaries Green Mountain Power and Vermont Gas Systems. There, it operates in the electricity production market and the electricity and natural gas distribution market.
The main natural gas distributor in Québec was created during the first nationalization of electricity in Québec, in 1944. By bringing Montreal Light, Heat and Power under state control, the new Quebec Hydroelectric Commission, better known as Hydro-Québec, not only took charge of the company's electricity assets, and also acquired a gas distribution network in Greater Montréal.
Near the end of the 1940s, industrialists began planning the construction of a pipeline that would connect Alberta and the large cities of Ontario. Hydro-Québec was approached to extend the pipeline toward Montréal. Several meetings were organized, and the Quebec Hydroelectric Commission ordered internal studies and sought expert advice. In March 1954, the commissioners formed a committee to make a decision. The committee recommended replacing industrial gas with natural gas from Western Canada, a conversion that would be of some benefit to the public utility. The Commission's President, L.-Eugène Potvin, instead recommended selling the gas sector to a private company. This solution was adopted and the Commission adopted a resolution to divest itself of all its gas assets, which was approved by the Duplessis government. Negotiations began with several groups and the sale of the network to the Quebec Natural Gas Corporation was concluded in the spring of 1957.
In 1969, the company was renamed Gaz Métropolitain.
In 1985, the company acquired Gaz Inter-Cité Québec (which served eastern Québec) and Gaz Provincial du Nord (which served Abitibi-Témiscamingue). It became a subsidiary of Noverco.