Olswang and Taylor Wessing are advising on the £400m merger between accountancy firms BDO and PKF, news of which was confirmed today (7 November).

The merger, which is planned to go live in early 2013, will create an accountancy firm with combined revenues of almost £400m and around 3,500 staff in the UK.

Olswang is advising long-term client BDO led by corporate partner Tony Leifer, with Taylor Wessing acting for PKF led by corporate partner Peter Kempe.

BDO is the UK's sixth-largest accounting firm, behind the 'Big Four' of PwC, Deloitte, KPMG and Ernst & Young and fifth-placed Grant Thornton, with PKF ranked 12th, according to Legal Week sister title Accountancy Age.

Accountancy Age's 2012 rankings show BDO had turnover of £281.5m for the last financial year, with £103.3m for PKF and £387m for Grant Thornton.

Olswang has advised BDO on a number of key transactions in recent years, including its £20m merger with tax advisory firm Chiltern at the close of 2007. The UK top 30 firm also advised BDO on the £4m acquisition of its Guernsey arm in February this year.

BDO has gained particular prominence in the legal sector over the last two years for its role as the liquidator of now-defunct law firm Halliwells. BDO partners Shay Bannon and Dermot Power have been overseeing the wind down of the business.

Click here for an interview with BDO and PKF managing partners Simon Michaels and Martin Goodchild from Accountancy Age.