WG&R UK operates a fleet of 45 vehicles, of which almost half are now powered by liquefied petroleum gas (LPG).
The company, which carries out the installation and maintenance of telecommunications equipment for major banks and building societies, has opted for Vauxhall's 1.6i Dualfuel Astravans which can run on both LPG and petrol.
It ran trials on the vehicles and the vans were received favourably by drivers. The company bunkers LPG at its head office which reduces the price of the fuel to 27p a litre.
As well as cost concerns, the decision to move the fleet towards greener fuels has also been driven by customer demand.
Transport manager Barry Puckering said: 'Many of the businesses we deal with want to know how many clean vehicles we have on our fleet as part of the tender process.
'We will be operating a number of the vans inside the London congestion charging zone from our Docklands-based office and will benefit from the 100% discount that the cleanest LPG vehicles attract, which has been another factor in the decision.'
With the move to greener vehicles, WG&R has also switched from outright purchase to three-year/90,000 mile full maintenance contract hire contracts with Lombard Vehicle Management. The Astravans are being supplied by Dixon Motors.