The outdoor media owner is running a trial of a new material made from recycled fibres, called Mondi Xtreme, supplied by South-African firm Xanita, and hopes to use it as a replacement for vinyl on all bus advertising.

CBS Outdoor commercial director Jason Cotterrell said the company held the vast majority of bus contracts in the UK, which allowed it to deliver national consistency.

"We are very excited about this initiative - once successfully trialled, this material will provide the first environmentally friendly solution to bus advertising without impacting negatively on the quality," Cotterrell added.

"Having received full backing from the bus companies, this alternative will potentially be made available to clients in the very near future."

The material is made from recycled paper and board, and can also be recycled at the end of a campaign, unlike vinyl.

Prices were not disclosed, but it is understood to be more expensive than the current material, however, it is less labour intensive, giving CBS a commercial incentive.

The trial will last six weeks and will take place on 15 buses in Newcastle and 30 in Manchester, with bus companies First Group, Stage Coach and Arriva.

CBS has no plans to use the material anywhere except buses, because it is rolling out dry-posting on the London Underground. This technique is environmentally superior because it removes the need for wet glue.

More than 20 stations in prime central stations - including Bond Street, Piccadilly, Oxford Circus, Green Park, Kings Cross, Charing Cross, Knightsbridge, Victoria, Queensway - have dry posting, and CBS plans to replace 95% of its estate with dry-posting over the next few years.

Unlike vinyl, the recycled material from Xanita cannot be back-lit. This is not a problem on buses, but would limit its utility for CBS' competitors, which specialise in street furniture and billboards.