OTTAWA -- The federal government is providing some relief to Canada's air transportation sector, one of the many industries hit hard by the COVID-19 pandemic.

Ottawa is waiving rent payments from March to December for 21 airport authorities, money that’s usually deposited directly into the pocket of the federal government each month. The government has also pledged to provide "comparable treatment" for PortsToronto, which operates Billy Bishop Toronto City Airport.

"The support will help airports reduce cost pressures and preserve their cash flow as they deal with the effects of COVID-19 on their revenue streams. This will provide relief up to $331.4 million, reflecting payments in the same period of 2018," reads the press release published on Tuesday.

The measures are a component of the Liberals' broader economic plan to mitigate the impacts of COVID-19 on Canadian businesses and the economy at large.

"We recognize the impacts that the COVID-19 pandemic continues to have on people and the economy, and that certain sectors, such as the air transportation industry, have suffered tremendously," said Finance Minister Bill Morneau.

"The support provided today is the next step in Canada’s COVID-19 Economic Response Plan to help workers and businesses get through this unprecedented time of turmoil."

The 21 airport authorities that will receive relief are:

St. John’s International Airport Authority

Gander International Airport Authority Inc.

Halifax International Airport Authority

Charlottetown Airport Authority Inc.

Saint John Airport Inc.

Greater Moncton International Airport Authority Inc.

Fredericton International Airport Authority

Aéroport de Québec Inc.

Aéroports de Montréal

Ottawa Macdonald-Cartier International Airport Authority

Greater Toronto Airports Authority

Greater London International Airports Authority

Thunder Bay International Airports Inc.

Winnipeg Airports Authority Inc.

Regina Airport Authority

Saskatoon Airport Authority

Edmonton Regional Airports Authority

Calgary Airport Authority

Prince George Airport Authority Inc.

Vancouver International Airport Authority

Victoria Airport Authority

Relief will also be provided to PortsToronto, which operates the Billy Bishop Toronto City Airport and pays an annual charge to Transport Canada based on the revenues it earns under the terms of its letters patent.

The pandemic has also caused thousands of layoffs in the airline sector.

Starting this week, Air Canada will temporarily lay off 16,500 employees – 15,200 unionized workers and 1,300 managers – a process that will continue through to May.

"To furlough such a large proportion of our employees is an extremely painful decision but one we are required to take given our dramatically smaller operations for the next while," chief executive Calin Rovinescu said in a statement.

WestJet and Transat AT Inc. have also issued mass layoffs.