Sinead O'Callaghan

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Sinead is a corporate and commercial litigator with a broad range of domestic and international experience. Her particular focus is on banking and finance, civil and commercial fraud and trust disputes and professional negligence matters.

Sinead’s banking and finance experience includes acting for receivers appointed over a structured investment vehicle in respect of disputes with the vehicle’s bankers and noteholders and advising on claims arising from the mis-selling of interest rate swaps and other complex financial products.

Her civil and commercial fraud and trust dispute experience includes cases involving fraudulent misappropriation of assets, multi jurisdictional asset tracing exercises, breach of trust and conflicts in relation to the appointment and removal of trustees. Her professional negligence experience includes both acting for claimants and defending disciplinary investigations and/or prosecutions brought against professional services organisations by various professional bodies, including the Institute of Actuaries, the FRC and the Institute of Chartered Accountants. She has also advised on substantial IT/Telecoms outsourcing disputes and partnership and shareholder disputes.

Sinead has experience of mediation, arbitration (LCIA, ICC, LME and FOSFA) and expert determination and her work frequently involves liaising with overseas lawyers, forensic accountants and other expert disciplines.


Sinead obtained a BSc from Bristol University in Biological Sciences (specialising in Genetics) and was awarded distinctions in both the Common Practice Examination and Legal Practice Course, which she studied at the College of Law in London. Sinead trained with Theodore Goddard (subsequently named Addleshaw Goddard after a merger), qualifying as a solicitor in March 2003. Sinead worked for Addleshaw Goddard for four years following her qualification and then moved to Mayer Brown International, where she worked for three years as a senior associate before leaving that firm to join Cooke, Young & Keidan in January 2010.


Sinead has been ranked as a leading lawyer in the Chambers and Partners Guide and Legal 500 Guide for banking litigation and commercial litigation. The current edition of Chambers states that she is “very astute” and “very tenacious and also very driven.” Former editions have commented that Sinead is “co-operative and understanding” and that she has earned praise from clients for “strong commercial acumen and useful, practical advice”. The current edition of the Legal 500 Guide also states that she is highly rated.


Examples of Sinead’s cases which have been the subject of reported judgments include:

• Real Estate Opportunities Limited v. Aberdeen Asset Managers Jersey Limited, Aberdeen Asset Managers Limited, UBS Limited [2007].  Advising on the defence of a claim arising from the flotation of a split capital investment trust.

• North Shore Ventures Limited v Anstead Holdings Inc & Ors [2010] (First Instance) and [2011] (Court of Appeal).  Defending a very high value claim brought in the Commercial Court by a company whose shares are owned by the well-known Russian oligarch Boris Berezovsky.  The case considered the extent to which a lender is under a duty to disclose unusual facts to a prospective guarantor and whether the failure to do so renders a guarantee void.

• RBS v Highland Financial Partners LP & Ors [2010] and [2012].  A widely reported banking litigation case relating to a €500 million CDO issue of securities and the subsequent liquidation/valuation of the portfolio following the Autumn 2008 financial crash. The bank was subjected to strong judicial criticism for conducting a “sham” auction of leveraged loans and was found to have lied to and deceived its counterparty. On the back of the 2010 Judgment, in early 2011 Highland commenced proceedings in Texas against RBS for, inter alia, fraud, seeking damages of at least $100 million. This step prompted RBS to seek and obtain an interim anti suit injunction from the English Commercial Court. The trial to determine whether the anti suit injunction should be granted on a permanent basis took place in late January 2012 and Highland was successful in arguing that the anti suit injunction should not be granted on a permanent basis.

• Confidential ICC Emergency Arbitration Proceedings [2012]. In December 2012, Sinead was involved in successfully defending emergency arbitrator proceedings under the ICC rules. This is believed to be one of the first sets of proceedings of this kind as the ICC emergency arbitrator rules were only introduced in January 2012.

• Confidential [2014]. Sinead was involved in defending a Norwich Pharmacal application made in support of high value and high profile proceedings in Mexico.

• Sinead also acted on a pro bono basis for Justice, a leading civil liberties organisation, in respect of its intervention in the House of Lords appeal in R (on the application of Corner House Research and others) v Director of the Serious Fraud Office [2008].  This was a judicial review of the decision of the Serious Fraud Office to halt investigations into alleged bribery on the part of BAE Systems Plc in respect of a Saudi arms deal.


Sinead is a member of the Law Society of England and Wales, the Young International Arbitration Group and the Irish International Business Network.