Malaysia Airlines and Singapore Airlines will scrap from June a deal that allows passengers to go on walk-in flights under a shared shuttle service, the flag carriers said on Friday.

But the termination of the 25 year old shuttle agreement, on a route that is one of the most profitable for Malaysia Airlines, will not cut frequencies or the variety of fares available on the route, they said in a statement.

Under the deal, the two carriers charge passengers who turned up at the airport on standby for the next flights for a common fare.

"The progressive deregulation of the Singapore-Kuala Lumpur route and the ever-increasing use of the Internet for a variety of transactions such as booking of tickets and check-in (even at the last minute), has changed the travel landscape, removing the need for a shuttle service," the statement added.

The route is also being taken up by budget carriers such as Air Asia, despite strong objections by the flag carriers.