Transport for London (TfL) and London Underground have united to appoint a joint panel for major projects work.

A shortlist of 18 firms have been invited to tender for panel places, with the new panel – which carries a four-year term – set to take effect from July when London Underground's present panel arrangements expire.

The new panel will deal with current projects including London Underground's ongoing investment programme and TfL's new Thames Gateway Bridge, as well as various transport projects for the 2012 Olympic Games. The process is being overseen by London Underground director of legal Sarah Atkins and TfL director of legal and compliance Gareth John.

TfL currently uses a number of firms for projects work, with Herbert Smith advising the body on the development of the East London Line, Freshfields Bruckhaus Deringer acting on the re-development of the north London Silverlink train line, Ashurst overseeing work on the Docklands Light Railway and Simmons & Simmons handling the congestion charge.

TfL's existing arrangements with Eversheds for mainstream operational work will not be affected. John and Atkins said they would be looking for firms that can demonstrate a commitment to London mayor Ken Livingstone's economic, social and environmental strategies.

In a statement, John said: "This is an opportunity to clarify expectations and drive the best value and efficiencies for TfL. We are also keen to ensure that the firms we work with reflect our own values regarding equality, inclusion and sustainable procurement."