Sen. Charles Schumer is calling for a federal investigation of airlines who won’t allow their fares to show up on third-party websites like Expedia and Orbitz.

The New York Democrat says Sunday that the practice prevents consumers from seeing all their options when booking a fight.

The Justice Department is already investigating possible collusion among major airlines to limit the number of available seats to keep fares high. Schumer says the investigation should be expanded to look at how airlines restrict access to their fares on third-party sites.

Schumer says the airlines appear to be trying to drive consumers to their own websites, but he says that limits competition and makes it harder for consumers to find the best deal on a flight.

(AP)