Porter Airlines has been ordered to revise its compensation procedures for Canadian passengers travelling to the U.S. when they are bumped from their flights and refund the fares of those who can't be transported to their destination.

In a decision issued Friday, the Canadian Transportation Agency found that some of Porter's tariff rules are "unreasonable" in that they create the impression that passengers may not have the right to compensation in some instances and do not spell out clearly that passengers are entitled to monetary compensation.

The agency reconfirmed passengers' right to be "refunded for the unused portions of their ticket if the carrier is unable to provide transportation ... within a reasonable period of time."

But it also said that if the airline can show that the scheduling irregularity occurred for "reasons beyond its control" and that it took "all reasonable measures" to avoid it or that it was impossible to take such measures, it will not have to compensate passengers for the segments of their trip already travelled.

The decision was the result of a complaint launched by passenger rights advocate Gabor Lukacs over Porter's policy of compensating bumped passengers travelling from the U.S. but not those travelling from Canada. Lukacs has launched several complaints in the past about airlines' compensation procedures.

For international flights departing from the U.S., the compensation for delays of less than four hours is 200 per cent of the airfare up to a maximum of $650 US. For delays of more than four hours, it is 400 per cent of the airfare up to a maximum of $1,300 US.

The agency ruled that Porter must offer passengers the choice of being compensated in cash or flight vouchers.

'[The CTA] ordered Porter to implement the U.S. denied-boarding compensation scheme on all international flights," said Lukacs in a press release.

He said he is glad the airline can "no longer discriminate against Canadian passengers." 

The airline has until Feb. 28 to amend its tariff rules.

The agency did not side with Lukacs on his argument that Porter should be made to comply with the voluntary code of conduct that Air Canada, Air Transat and WestJet agreed to follow in 2008.  Lukacs said he is "puzzled" as to why Porter was given "special treatment."