UK: English Court Of Appeal Considers Disclosure Of Arbitral Appointments In Related Or Overlapping References

In Halliburton Company v Chubb Bermuda Insurance Ltd [2018] EWCA Civ 817, the English Court of Appeal was asked to consider:

  1. whether it is possible for an arbitrator to accept multiple appointments with overlapping reference and one common party, without giving rise to doubts over impartiality?
  2. at what point should an arbitrator disclose these further appointments – if at all?

The Court of Appeal dismissed the appeal, stating that, on the facts of the case, there was no real possibility that the arbitrator was biased when viewed from the perspective of a "fair minded and informed observer". Nevertheless, the Court held that, in accordance with English law and best practice in international arbitration, disclosure should have been made.


On 20 April 2010, there was an explosion at the Deepwater Horizon oil rig, which was owned by Transocean Holdings LLC. BP Exploration and Production Inc. (BP) was the lessee of the rig and Halliburton Company (Halliburton) provided cementing and other services for BP. Prior to the explosion, both Transocean and Halliburton had purchased excess liability insurance from Chubb Bermuda Insurance.

Halliburton failed in its attempt to claim under the insurance policy, and as a result, decided to commence arbitration against Chubb. The two parties could not agree on the choice for the third arbitrator, so the High Court appointed 'M' (Reference 1).

Prior to his appointment in June 2015, M disclosed that (i) he had previously acted as arbitrator in cases where Chubb was a party and (ii) he was currently appointed as arbitrator in two references, both of which involved Chubb.

In December 2015, M accepted an appointment by Chubb in a case involving Transocean (Reference 2). In August 2016, M accepted an appointment as substitute arbitrator in another case with Transocean, this time against a different insurance company (Reference 3). Neither Reference 2 nor Reference 3 was disclosed to Halliburton.

Halliburton applied to the court to have M removed as the arbitrator in Reference 1, under section 24(1)(a) of the Arbitration Act 1996, which provides that an arbitrator can be removed when "circumstances exist that give rise to justifiable doubts as to his impartiality".

The application was dismissed on the basis that there was nothing in the acceptance of References 2 and 3 that gave rise to an appearance of bias or impartiality. M maintained that he remained independent and impartial in all the cases. M explained that, although the References all arose out of the Deepwater Horizon explosion, they did not raise the same, "or even similar", issues. He stated that he had not disclosed the two appointments by Transocean, because it did not occur to him at the time that the IBA Guidelines on Conflict of Interest in International Arbitration obliged him to do so. Both sides accepted this explanation as truthful. However M accepted, "with the benefit of hindsight, that it would have been prudent" for him to have done so.

Popplewell J dismissed the claim in the lower court, and Halliburton appealed.

The appeal

The crux of Halliburton's appeal was its contention that the judge at first instance failed to have proper regard to the unfairness that may arise when an arbitrator accepts appointments in overlapping references with only one common party. Halliburton expressed concern over the potential for the common party in the references to be put in an advantageous position by tailoring its submissions to best suit the approach of the arbitrator, or sharing relevant information with the arbitrator, without the knowledge of the other party. In a situation where one party has information about facts and arguments known to the arbitrator and directly relevant to the case, the fair minded observer would conclude that that constitutes an unfair advantage.


The judgment in Locabail (UK) Ltd v Bayfield Properties Ltd [2000] QB 451 indicated that it is "generally desirable" to disclose any matter that can give rise to a 'real' danger of bias. In Guidant LLC v Swiss Re International SE [2016] EWHC 1201, the judge acknowledged that fears over inside knowledge were a legitimate concern, while at the same time recognising that a common arbitrator does not, in itself, justify an inference of apparent bias; "[s]omething more is required."

The Court of Appeal also referred to Almazeedi v Michael Penner [2018] UKPC 3, where there is clear support for disclosure, in circumstances where the non-disclosure of certain facts may give rise to doubts about a judge (or arbitrator)'s impartiality. The authorities referred to in the judgment concurred that there are practical advantages to disclosure and that the test is an objective one; the decision is to be made according to what the fair-minded and informed observer "would or might" conclude. In borderline cases, disclosure should be made. In cases where an arbitrator has failed to disclose circumstances that could result in doubts about his impartiality, the Court of Appeal stated that the arbitrator had not displayed the "badge of impartiality".

The Court noted that certain arbitral rules and guidelines impose a stricter test of disclosure than English law. The IBA Guidelines, for example, require disclosure of facts or circumstances that may, in the eyes of the parties, give rise to doubts as to the arbitrator's impartiality or independence (emphasis added). By contrast, the Court confirmed that English law still applies the "more certain standards" of an objective observer when considering whether disclosure should be made. Moreover, arbitrators are required to disclose only circumstances known to them at the time.

The Court confirmed the position under English law as follows: "disclosure should be given of facts and circumstances known to the arbitrator which...would or might give rise to justifiably doubts as to his impartiality".

Apparent bias

The Court of Appeal dismissed the argument that accepting multiple appointments with only one common party would, in itself, justify an inference of apparent bias. The Court understood that, from Halliburton's perspective, legitimate concerns arose from M's conduct, however "something more" would be required to justify doubts as to M's impartiality in the eyes of an objective observer. Arbitrators are assumed to be trustworthy enough to approach each case with an open mind, and to make decisions purely on the facts before them. Moreover, the facts showed that the non-disclosure was accidental, even if, as a matter of best practice, disclosure should have been made.


The Court dismissed the appeal. The overlapping issues within the multiple appointments did not of itself give rise to any significant concerns, and if the objective test was applied, a fair-minded and informed individual would not conclude that an accidental failure to disclose would give rise to justifiable doubts as to M's impartiality. The Court held that, as a matter of good practice in international arbitration and as a matter of English law, M should have disclosed the further reference to the Appellant. However, the Court agreed with the judge at first instance that the fair-minded and informed observer, having considered all the facts, would not conclude there was a real possibility that M was biased.


The decision in Halliburton v Chubb has clarified that arbitrators can accept more than one appointment with overlapping subject matters, without necessarily giving rise to doubts about their impartiality. The judgment further confirms that English law will apply the "objective observer" test when determining doubts as to an arbitrator's impartiality, despite arbitral rules and guidelines applying a more subjective test. What emerges clearly is that each case will be determined on its facts, and that there is strong judicial support for disclosure where there is any doubt in the arbitrator's mind about potential appearance of bias. This is unsurprising, and reflects arbitral best practice internationally.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

Similar Articles
Relevancy Powered by MondaqAI
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Related Articles
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of

To Use you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions