Produced in Northern Ireland, the 10.9-metre single-deck buses have been supplied on seven-year operating leases.
The buses are fitted with 454kWh batteries and can cover up to 200 miles on a single charge, with capacity for up to 60 passengers in Transport for London (TfL) spec.
Newly in service on TfL’s Route R70, the Electroliners run from Hampton to Twickenham and on to Richmond, in south-west London, with a single charge typically sufficient for a working day.
Alastair Willis, commercial director at Transport UK London Bus, said: "We started our decarbonisation journey in 2020. All six of our London depots are now electrified with DC chargers, and approaching a third of our 900-strong bus fleet is electric.
"These latest additions, replacing diesel models, retain that momentum and allow us to continue to play our part in helping the Mayor of London deliver his clean-air pledge. This will see only zero emission buses operating in the capital from 2030."
Martyn Bellis, commercial Director for coach & bus at Asset Alliance Group, added: "We were pleased to be able to assist Transport UK London Bus with their ongoing transformation.
"This latest deal underlines the key role Asset Alliance Group is playing in facilitating the uptake of electric buses in the capital on behalf of the major bus operators and TfL."