Gaz-Métro spokeswoman Catherine Houde said the first call was placed shortly before 11 a.m. on Saint-François-Xavier Street in Old Montreal.
The leak was caused by an excavation incident and about 50 people were forced from buildings by firefighters as precaution.
The issue was resolved shortly after 3:30 p.m. but authorities continued testing the air in the area to make sure people could re-enter their buildings.
Gas leak in Place Ville-Marie
Houde said a Gaz-Métro worker also plugged a gas leak in Place Ville-Marie.
People reported a strong smell of gas in the building's food court around 1:20 p.m.
Firefighters proceeded with an evacuation but people were able to re-enter the building shortly after 2:15 p.m.
The leak resulted from problems with the natural gas regulator in the building.