Legal and professional fees relating to the collapse of Lehman Brothers nearly seven years ago are still averaging £3m a month, according to the latest progress report from administrator PwC.

Spending stemming from the bank's September 2008 collapse hit £40m for the 2014 calendar year, with the fees evenly split across the first and second half of the year.

The administrator is predicting an additional £10m in legal and professional fees will be spent in the first half of 2015, taking the total forecast for the period to £30m. 

Since PwC was appointed as administrator in 2008, more than £343m has now been spent on legal and professional fees relating to creditors' claims. 

According to the report the expected increase in fees reflects more activity in the "Waterfall I and II proceedings", which relate to claims over rights to surplus funds in one of Lehman's holding companies, as well as other unrelated disputes. 

Part of the Waterfall II application was heard in the Court of Appeal in March in a hearing in which Linklaters, DLA Piper, Dentons, Weil Gotshal & Manges and Freshfields Bruckhaus Deringer all advised.

According to PwC's report, that claim and related counterparty litigation has been "offset by a reduction in activity relating to trust estate, affiliates and general counterparty disputes".

The administrator has revised down the future total estimated costs of the wind down by £60m, predominantly reflecting a reduction in expected litigation.

Linklaters has served as the main legal adviser to PwC since it was appointed as the administrator in Europe, with a team of more than 100 lawyers and 20 partners first enlisted in the banking giant's collapse. 

In the first six months after Lehman's failure legal fees totalled £77m, more than triple the average monthly spend today.