The Marriott call centre in Fredericton will be closing its doors, putting 265 people out of work.
Mayor Brad Woodside says the closure will take effect in February.
"The most exciting part of being mayor is announcing new jobs. The toughest part is announcing job losses," he posted on Twitter.
He later told CBC News that the layoffs would have wider ramifications.
"The financial impact and the social impact is going to be quite dramatic. It's not just  people. It's those that service that sector," he said.
"There's a lot of money generated outside the call centre where the employees are working. So there's a whole lot of things involved in this that make it a very sad day."
The company has not yet explained why it's shutting down its Fredericton operations.
The Marriott Global Reservation Sales and Customer Care centre, located on Main Street, is one of the city's largest private sector employers.
It's a reservation centre for Marriott Hotels. Staff answer incoming calls and book hotel rooms in more than 60 countries around the world.
The Fredericton call centre opened in 1999.
The Marriott also has a call centre in Sarnia, Ont., as well as several centres in the United States.