Quinn Emanuel Urquhart & Sullivan is set to hire two London arbitration partners from Allen & Overy (A&O), Stephen Jagusch and Anthony Sinclair, with the hires coming just days after the US litigation specialist launched in Hamburg with a team from A&O.

Jagusch, who has been a partner at A&O since 2002, is a top-rated arbitrator with a specialisation in international commercial and investment treaty arbitration, while Sinclair's practice covers the energy and natural resources, telecoms, utilities and infrastructure sectors. He was promoted to partner in 2011.

The two partners handed in their notice this week but have not yet started negotiating their exit terms from A&O, which could theoretically hold them to a one-year notice period. Jagusch will lead Quinn's international arbitration practice when he joins.

A&O said in a statement: "We can confirm that Stephen Jagusch and Anthony Sinclair have given notice of their intention to resign from Allen & Overy at the end of the 2013 financial year."

John Quinn, the US firm's founder and managing partner, said: "We understand that the effective date of Stephen and Anthony's resignation was a few days ago – but that Allen & Overy have indicated that they will hold them to a contractual 12-month notice period. We are disappointed that the firm has taken this position but obviously hopeful that we can negotiate their earlier release.

"Whilst we understand that A&O see this as a necessary defensive step, our view that is that it is unhelpful to clients and ultimately reflects badly on the firm. We hope that sense will prevail."

A&O has a further three arbitration partners in London, including Judith Gill QC, who leads the firm's 35-partner global international arbitration group.

News of the London hires, which represent Quinn's first dedicated arbitration partners in London, comes after the firm  launched a Hamburg office earlier this month (1 May) with the hire of A&O's local intellectual property head Nadine Herrmann, along with a six-lawyer team, to lead the office.

Quinn had previously opened its first German office in Mannheim through the hire of A&O patent litigation partner Marcus Grosch in 2010. Meanwhile in 2009, Quinn also hired A&O's then US co-head Dan Cunningham for its New York practice.

The US firm set out ambitious plans to expand across Asia and Europe earlier this year, earmarking Germany and Switzerland for office launches within the next two years, while an office in either Hong Kong or Singapore is planned for a later date.

Quinn launched its London office in October 2008, with the office currently counting eight partners.

London co-managing partner Richard East commented: "We have been looking for leading practitioners in this space for years. In order to become a global leader in arbitration it is vital to have multi platforms, and we now have leading practitioners in the US, London and Moscow. We will add further capability in due course."