Herbert Smith Freehills and Eversheds have earned a combined total of more than £70m from work for Transport for London (TfL) since 2008, a freedom of information request submitted by Legal Week has revealed.

The two firms are the biggest earners from contracts awarded by the transport body over the five-year period to the end of 2012, with Herbert Smith billing £42.2m and Eversheds £31.5m.

Key TfL work Herbert Smith has handled in recent years includes advising on the upgrade and extension of the East London Line, and the administration of transport group Metronet, the UK's first-ever public-private partnership (PPP) insolvency.

Eversheds was appointed to TfL's panel in 2007 to advise on a range of mainstream operational work, although the firm did not comment on any specific elements.

Since 2008, the duo has earned considerably more than Freshfields Bruckhaus Deringer, the third biggest recipient of TfL fees totalling £5.9m.

In 2011, the magic circle firm was hit with a £140m negligence claim relating to advice it gave the TfL-run London Underground Ltd in 2002 over the Metronet PPP, a case that is set to go to court later this year.

Other top billers include Bircham Dyson Bell (£5.3m), which advised on planning and real estate aspects of the £50m Emirates Air Line cable car across the Thames, Wragge & Co (£3.8m), Simmons & Simmons (£3.7m), Ashurst (£3.7m), CMS Cameron McKenna (£3.2m) and Manches (£3m).

TfL's annual legal spend has fallen steadily since 2009, when it paid out £30.5m to law firms, with the figure slipping to £22m in 2010 before falling further in 2011 and 2012 to £16.6m and £13.9m respectively.

TfL said the dip marked a return to the norm following significant legal work between 2008 and 2010, such as arbitrations arising from the Connect private finance initiative telecoms project, the Metronet administration, the PPP Periodic Review for Tube Lines and the subsequent acquisition of Tube Lines.

In October, TfL unveiled its new legal panel, with the number of advisers cut from 12 to 11 and SNR Denton, Trowers & Hamlins and Lewis Silkin newly appointed to the roster.

Despite featuring high up on the list of law firms called upon by TfL in the past, both Manches and Bircham Dyson did not feature on the revamped panel.