Airlines are charging too much to change flights, especially on international routes. 

That's what a major consumer group says after it last week petitioned the U.S. Department of Transportation to put a $100 cap on change fees for international flights.

FlyersRights.org says that change fees for international flights, which at times have been as low as $50, now go as high as $750.  In addition, the group says the fee is not commensurate with the airlines' actual cost of making the change. 

Paul Hudson, president of the group FlyersRights.org, filed an 18-page petition on Feb. 11 asking D.O.T  to regulate international change fees.

The move comes amid growing frustration with increasing airline fees, which have helped boost carriers’ bottom line. Today, consumer advocates say that airlines now see these change fees as a revenue stream, and have been raised them to unfair levels.

D.O.T can either accept or reject the petition, and FlyersRights.org could potentially appeal in federal court.