(Reuters) - Air Canada said on Wednesday it will start charging for bigger carry-on bags from passengers opting for its lowest-priced basic fare for North America routes starting Jan. 3.

Passengers will now have to pay for larger items such as roller-boards or duffel bags, or large backpacks under the new terms. The carrier will charge C$35 for the first bag and C$50 for a second.

United Airlines has implemented a similar policy, requiring basic economy passengers to pay at least $35 for carry-on bags.

All travelers can still bring a small personal item that fits under the seat, such as a purse or laptop bag.

Airlines have increased checked baggage fees for North American flights, citing rising maintenance and labor contract costs.

Air Canada will also charge basic fare passengers an additional charge if they wish to change their seat from the one assigned at check-in.

The Montreal-based flag carrier added it will increase checked baggage allowance for customers traveling worldwide on its comfort economy fare, with passengers now entitled to check two complimentary bags.