TORONTO -- Just as new rules meant to protect air passengers' rights comes into effect, information is coming to light about four airlines being fined for breaking the existing regulations.

The Canadian Transportation Agency says Air Transat, Delta Air Lines, United Airlines and Air France were all issued fines on Nov. 25.

The largest penalty was given to United, which was fined a total of $10,000 for four separate offences. The transportation agency found that United failed to display required information about passenger rights at boarding gates and self-service check-in machines in Halifax and Calgary on Sept. 11. A spokesperson for United said that the airline has paid the fine and is committed to meeting all regulations.

Delta was fined $2,500 for violating the same requirement as United at a boarding gate in Calgary on the same day.

The rule that signage notifying passengers of their rights must be displayed at check-in stations and boarding gates came into effect in July, as part of the first round of the federal government's overhaul of passenger protections.

Also added in July was a requirement that passengers stuck on airplanes waiting on airport tarmacs be provided reasonable amounts of food, based on the time of day and length of the delay.

Air Transat was fined $2,500 for not doing this on a July 29 flight in Rome. A lack of food was only one of several concerns voiced by passengers on that plane, some of whom told CTVNews.ca that there were significant issues with air circulation and water availability. An Air Transat spokesperson told CTVNews.ca in a statement that the airline is concerned for passengers' well-being and apologizes "to any passenger who might have experienced discomfort on that occasion, despite our best efforts."

Air France, meanwhile, was fined for breaking rules that have been in effect for much longer. The transportation regulator docked the airline $1,200 for offences related to not properly labelling flight charges on its online booking system.

THE RULES HAVE CHANGED AGAIN

The second wave of changes to Canada's air passenger protection regulations came into effect on Sunday.

These modifications include a requirement that children be seated near their parents when they are travelling together.

Overall, though, the latest update primarily focuses on outlining minimum compensation levels for passengers whose flights are delayed or cancelled for reasons that are within an airline's control and not related to safety.

Larger airlines will have to pay a minimum of $400 for three-hour delays, rising to $1,000 for delays of nine hours or more. For smaller airlines, those numbers are $125 and $500 respectively.

Passengers must also be given free Wi-Fi or other access to the internet if delays last more than two hours, and free accommodations and transport for delays that extend into the night. In some cases, airlines are required to rebook passengers after lengthy delays – even if that means buying them a ticket for another airline.

A group of airlines backed by the International Air Transport Association has launched a legal challenge of the regulations, claiming they violate international standards.

Passenger rights advocates, meanwhile, argue that the rules don't go far enough, allowing airlines to delay flights for unforeseen maintenance or mechanical problems without compensating passengers.

With files from CTVNews.ca's Jackie Dunham