The frequency of buses on the routes will increase
The use of 83 bendy-buses is to be phased out on three routes, Transport for London (TfL) has said.
Routes 507 and 521 will be operated with 12m single deck buses from summer 2009 when the current contract expires.
Route 38 with will be replaced with a double-decker bus from next autumn. The frequency of buses will be increased.
London Mayor Boris Johnson pledged to scrap bendy-buses during his election campaign but the move has been condemned by London's travel watchdog.
Bendy-buses replaced the traditional Routemaster as they were seen as inaccessible to wheelchairs or pushchairs.
Awkward elongated bulk
But Mr Johnson pledged to get rid of the articulated buses , saying they were "never suited to London's roads".
On Friday he said: "Many Londoners, particularly cyclists, see the awkward elongated bulk of the bendy-bus as completely unsuitable for the city's streets, and during the mayoral election this became a huge issue.
"I am making sure the buses are removed in the most cost-effective way, and today's new contract announcement marks the beginning of the end for the bendy-bus in London."
TfL said in order to carry the same number of passengers, the frequency of buses on these routes will be increased.
But the London Travelwatch, London's independent travel watchdog, said the scrapping of bendy-buses on these routes represented poor value for money.
Its chief executive Janet Cooke said: "The costs of using conventional buses on these routes may be significantly higher than using bendy buses.
"We have estimated, and TfL has not disputed the figure, that additional costs on these three routes alone could be in the region of 12 to 13 million pounds per annum."
She added: "London TravelWatch believes that the use of articulated buses on routes with a high volume of passengers has overwhelming advantages, in terms of accessibility, manoeuvrability in limited road space and loading and dwell times.
"They are particularly suitable for use on routes which serve mainline railway termini, where numerous passengers arrive at stops in short spaces of time.
"We see no reason to scrap these buses."