LONDON (BLOOMBERG) - Ryanair Holdings is locking the cabin door on carry-on luggage for its lowest-paying customers and forcing them to check the bags for a fee to save time loading passengers on and off flights.

Starting Nov 1, Europe's biggest discount airline will only allow travellers who pay for priority boarding to bring the customary wheelie on-board along with one smaller item, the Dublin-based carrier said Thursday (Aug 23).

Non-priority customers can only bring a less-bulky item onto the flight, such as a handbag, backpack or laptop bag.

Carry-on bags - the wheeled suitcases created to fit in overhead bins - will be relegated to the hold and cost £8 (S$14) to stow, Ryanair said.

The airline said the move is aimed at speeding the boarding process and limiting flight delays.

The company, known as the most efficient operator in the industry, relies on quick turnarounds to squeeze profit out of its tight schedule of cheap flights.

The company billed the decision as a way to lower checked-bag fees by introducing the £8 fee, or £6 when booked online, for luggage weighing less than 10kg.

Currently, the cost is £25 for a bag up to 20kg.

Sixty per cent of customers will be unaffected, because they either pay for priority boarding already or travel with only a small bag, according to Kenny Jacobs, Ryanair's chief marketing officer.

"We expect that the other 40 per cent will either choose to buy priority boarding or a 10kg check bag, or will choose to travel with only one (free) small bag," he said in a statement.