Washington — The US Department of Transportation announced recently that it fined Mexican airline Volaris $130,000 for allegedly failing to inform travelers about baggage fees when buying a ticket.

This is the first such penalty since the DOT implemented a rule in January that required airlines to inform passengers that they may have to pay baggage fees.

The rule specifies that airlines must "clearly and prominently" disclose on the first web page that offers a fare for a customer's itinerary that additional fees for baggage may apply. Airlines must also show consumers where they can view the baggage fees. The rule applies to all airlines selling flights in the US, including foreign carriers.

The DOT claims that a search of flights on Volaris' website in the days after the rule was implemented failed to properly inform consumers that baggage fees were possible.

Volaris is the third-largest Mexican airline. It flies to more than 20 cities in Mexico and has flights to California, Las Vegas, Chicago, and Orlando.