Nearly 30 partners at international firm Olswang left the firm ahead of its merger with CMS and Nabarro, it emerged today. 

In total, 28 partners departed the firm between May 2016 and the end of April this year – documents filed on Companies House show. 101 partners worked at Olswang before the merger was agreed.

Eleven of the departures were from Olswang’s London office, which was based in High Holborn until staff moved into CMS’s Cannon Street office. Among the losses was former interim chief executive and patent specialist Michael Burdon, who joined international firm Simmons & Simmons.

Other partners from Paris, Germany and Singapore also departed.

According to similar filings for Nabarro, seven of its 108 partners departed during the same period.

The three-way merger was agreed in October last year and was completed in May this year. The combined firm, the world's sixth largest by headcount, trades as CMS and the name of the UK is CMS Cameron McKenna Nabarro Olswang LLP. 

Ahead of the merger the firms confirmed that around one-third of support staff from across the UK would be lost.