Dentons has hired Olswang's patent prosecution group co-chair Justin Hill. He will join Dentons in London as a partner and head of its European patent prosecution and opposition practices.

His start date is yet to be confirmed.

The news comes in the wake of Olswang's planned three-way merger with CMS UK and Nabarro, due to go live 1 May.

It is the second resignation from Olswang's intellectual property (IP) practice since news of the merger broke in September. Former Olswang London IP partner and co-head of life sciences Stephen Reese joined Clifford Chance at the start of October.

Hill first joined Olswang as patent prosecution co-chair in May 2013. Fellow co-chair and London IP partner Robert Stephen will now lead the group. Hill was previously head of European IP prosecution at McDermott Will & Emery.

His exit will leave Olswang with 15 partners in its global IP practice, according to its website.

Legal Week reported last month that Olswang partners had been given until 10 October to sign a lock-in agreement committing them to the merger, with those not agreeing to the lock-in set to move on before the go-live date of 1 May 2017.

Days after the firm first confirmed it was in merger talks with Nabarro and CMS UK, its restructuring head Alicia Videon joined McDermott Will & Emery as a partner in its London transactions practice.

Hill is the second IP hire for Dentons since it recruited London IP partner Campbell Forsyth from King & Wood Mallesons in August.

Dentons UK managing partner Brandon Ransley said: "Clients from the US and Asia increasingly require patent advice in Europe, and Justin's arrival enhances our capacity to meet this demand, while also representing a further step towards achieving our objective of building a leading global patent capability."

Other partner departures from Olswang this year include funds and regulatory partner Barry Stimpson, who joined Bond Dickinson's corporate department in July; former London competition head Howard Cartlidge, who is set to join DWF in September; head of telecommunications Purvi Parekh, who left in August; and former head of corporate, private equity and venture capital Stephen Rosen, who joined Cooley's new London office in January this year.

An Olswang spokesperson said: "We can confirm that Justin Hill will be leaving Olswang and we wish him well for the future."