OPINION
FACTS AND PRIOR PROCEEDINGS
Pursuant to a contract, Jean and Leonard Schmitz (“Appellants”) and Zilveti, Meris, and Prudential-Baehe Securities, Inc. (“Pru-Bache”) (collectively “Appellees”) submitted a dispute to arbitration before the National Association of Securities Dealers (“NASD”). Under the submission agreements, the dispute was to be arbitrated in accordance with the NASD’s A Code of Arbitration Procedure (1990) (“NASD Code”). Three arbitrators were chosen: John R. Conrad, Carolyn J. Yamasaki, and Richard G. MacMillan. Conrad, a lawyer, was chosen as chairperson of the arbitration panel.
The NASD Code requires each arbitrator to “disclose to the Director of Arbitration any circumstances which might preclude such arbitrator from rendering an objective and impartial determination.” NASD Code § 23(a). Specifically, an arbitrator must disclose (1) “[a]ny direct or indirect financial or personal interest in the outcome”; (2) “any ... financial, business, professional, family, or social relationships that are likely to affect impartiality or might reasonably create an appearance of partiality or bias”; and (3) any personal relationships with any party, its counsel, or witnesses. Id. These relationships must be disclosed whether maintained, presently or previously, by the arbitrators or “members of their families or their current employers, partners, or business associates.” Id. The NASD Code also requires arbitrators to make an investigation regarding potential conflicts of interest. NASD Code section 23(b) provides: “Persons who are requested to accept appointment as arbitrators should make a reasonable effort to inform themselves of any interests or relationships described in Paragraph (a) above.”
Each arbitrator in this case completed a disclosure form indicating affiliations, if any, with the parties to the arbitration and any other matter he or she believed was required to be disclosed. The parties were given these forms. Neither side objected to any of the three arbitrators. After a hearing, the three arbitrators found unanimously in favor of Appellees. A post-award investigation by Appellants then revealed the following facts: Conrad’s law firm represented the parent company of Pru-Bache, Prudential Insurance Co., in at least nineteen cases during a period of 35 years; the most recent representation ended approximately 21 months before this arbitration was submitted. Conrad had reviewed, prior to the hearing, documents stating that Prudential Insurance Co. was the parent company of Pru-Bache. Yet Conrad only ran a conflict check for Pru-Bache. He disclosed prior to the hearing none of the many Prudential Insurance Co. cases his law firm had handled. 1
Appellants challenged the arbitration award in district court. They alleged that the award should be vacated because Conrad was evidently partial under 9 U.S.C. § 10(a)(2). 2 The district court held that a party challenging an arbitration award must prove facts establishing a reasonable impression of evident partiality and that arbitrators are only bound to disclose facts of which they are aware at the time of the hearing. The court then found that because Conrad was unaware of his law firm’s conflict at the time of the hearing, Appellants had failed to show facts meeting their burden of proof. On this basis, the district court found that no evident *1045 partiality was present. From that decision, Appellants appeal.
DISCUSSION
Appellants question (1) the legal standard employed by the district court and (2) the application of that legal standard to facts. This court reviews both issues de novo.
Pullman-Standard v. Swint,
I. The Legal Standard
Appellants argue that
Commonwealth Coatings Corp. v. Continental Cas. Co.,
The district court held that “the arbitrator ... was entirely fair and impartial,”
id.
at 151 n. *,
The parties in the instant ease dispute what legal standard
Commonwealth Coatings
establishes. Their disagreement is in part fueled by misunderstanding of Justice White’s concurrence in
Commonwealth Coatings.
Justice White wrote a concurring opinion in
Commonwealth Coatings,
which Justice Marshall joined. Because three other justices dissented, the vote of either Justice White or Justice Marshall was necessary to the formation of a majority voting for reversal. Justice White’s concurrence has therefore been given particular weight.
See Middlesex Mut. Ins. Co. v. Levine,
The parties also dispute the meaning of our case law discussing
Commonwealth Coatings.
We have discussed
Commonwealth Coatings
twice while formulating a substantive standard to apply in adjudicating whether an arbitrator is biased, first in
Sheet Metal Wkrs. Int’l Ass’n, Local 420 v. Kinney Air Cond. Co.,
*1046
Appellants urge us to employ in this ease the “appearance of bias” language from the
Commonwealth Coatings
majority opinion. Appellants note that the
Kinney Air
court, when stating that
Commonwealth Coatings
was a nondisclosure case, cited only to the
Commonwealth Coatings
majority opinion.
See
In rebutting Appellants’ arguments, Appel-lees also cite to
Kinney Air
as well as
Toyota of Berkeley.
Although these two cases involved allegations of actual bias rather than a failure to disclose a conflict, in these cases the court implied that
Commonwealth Coatings
established a “reasonable impression of partiality” standard. In
Toyota of Berkeley
and
Kinney Air
we employed this standard in analyzing whether actual bias was shown.
Toyota of Berkeley,
Appellees also claim that Justice White’s concurring opinion rejects the “appearance of bias” language. Appellees imply that the “appearance of bias” language is derived from
Tumey v. Ohio,
in which the partiality of a judge was at issue. Moreover, the “appearance of bias” language appears roughly equivalent to the standard set forth in 28 U.S.C. § 455, which requires a federal judge to recuse himself when his “impartiality might reasonably be questioned.” Thus, Ap-pellees assert, Justice White’s statement that arbitrators are not to be held to the standard applicable to judges implicitly rejected the “appearance of bias” language.
Neither party is entirely correct. How to apply
Commonwealth Coatings
in a nondisclosure case is an issue of first impression in the Ninth Circuit. Other courts facing the same issue have held that “evident partiality” is present when undisclosed facts show “a reasonable impression of partiality.”
Levine, 675 F.2d
at 1201;
see Sanko S.S. Co. v. Cook Indus., Inc.,
We do not rest our decision on any conflict Justice White’s concurrence may have with the
Commonwealth Coatings
majority opinion, however. Despite Justice White’s rejection in this context of the partiality standard applicable to judges, he does not expressly reject the “appearance of bias” language. Though the concurrence may show an apparent contradiction, the conflict dissipates when one recalls that the context in which arbitrators and judges operate and the functions they perform differ. Expert arbitrators will nearly always, of necessity, have numerous contacts within their field of expertise.
Though
Toyota of Berkeley
and
Kinney
'
Air
provide some support for the proposition that
Commonwealth Coatings
establishes “reasonable impression of partiality” as a legal standard, both the facts and factual analyses of those eases are inapposite to the instant nondisclosure case. Both involve allegations of actual bias rather than evident partiality from failure to disclose.
Toyota of Berkeley,
Notwithstanding the factual dissimilarity of
Toyota of Berkeley
and
Kinney Air
with nondisclosure eases, both
Toyota of Berkeley
and
Kinney Air
employ the “reasonable impression of partiality” standard taken from
Commonwealth Coatings,
a nondisclosure case.
Toyota of Berkeley,
The policies of 9 U.S.C. § 10 also support the notion that the standard for nondisclosure cases should differ from that used in actual bias cases. In a nondisclosure case, the integrity of the process by which arbitrators are chosen is at issue. Showing a “reasonable impression of partiality” is sufficient in a nondisclosure case because the policy of section 10(a)(2) instructs that the parties should choose their arbitrators intelligently.
Commonwealth Coatings,
Perhaps the notion that a reasonable impression of bias does not add up to actual bias prompted the
Kinney Air
court to state: “The appearance of impropriety, standing alone, is insufficient.”
*1048
Given these differences, we think it entirely appropriate that the
Toyota of Berkeley
and
Kinney Air
courts distinguished nondisclosure cases as inapposite, even though
Toyota of Berkeley
and
Kinney Air
use a standard derived from
Commonwealth Coatings. Toyota of Berkeley,
II. Conrad’s Firm’s Representation of Prudential
Appellants claim that Conrad should have disclosed his law firm’s former legal representation of Prudential Insurance Co., the owner of Appellee Pru-Bache. Appellants argue also that if Conrad did not know that Prudential Insurance Co. was a client of his firm, he should have investigated.
The district court rejected both contentions, holding that Conrad was not aware of the conflict and had no duty to investigate. Some courts have considered an arbitrator’s lack of knowledge as a factor in determining whether evident partiality was present.
See, e.g., Levine,
Appellants have a better argument. Though lack of knowledge may prohibit actual bias, it does not . always prohibit a reasonable impression.of partiality. As Appellants argue, an arbitrator may have a duty to investigate independent of its
Commonwealth Coatings
duty to disclose. A violation of this independent duty to investigate may result in a failure to disclose that creates a reasonable impression of partiality under
Commonwealth Coatings.
For instance, the parties can expect a lawyer/arbitrator to investigate and disclose conflicts he has with actual parties to the arbitration.
Close v. Motorists Mut. Ins. Co.,
Requiring arbitrators to make investigations in certain circumstances gives arbitrators an incentive to be forthright with the parties, honestly disclosing what arbitrators might otherwise have an incentive to hide. Commonwealth Coatings establishes that the parties rather than the arbitrators or the courts should be the judges of the partiality of arbitrators:
In many cases the arbitrator might believe the business relationship to be so insubstantial that to make a point of revealing it would suggest he is indeed easily swayed, and perhaps a partisan of that party. But if the law requires the disclosure, no such imputation, can arise. And it is far better that the relationship be disclosed at the outset, when the parties are free to reject the arbitrator or accept him with knowledge of the relationship and continuing faith in his objectivity, than to have the relationship come to light after the arbitration, when a suspicious or disgruntled party can seize on it as a pretext for invalidating the award. The judiciary should minimize its role in arbitration as judge of the arbitrator’s impartiality. That role is best consigned to the parties, who are the ar *1049 chitects of their own arbitration process, and are far better informed of the prevailing ethical standards and reputations within their business.
In this case, Conrad had a duty to investigate the conflict at issue. Section 23(a) & (b) of the NASD Code requires arbitrators to “make a reasonable effort to inform themselves of any” “existing or past financial, business, [or] professional ... relationships [that they or their employer, partners, or business associates may have] that are likely to affect impartiality or might reasonably create an appearance of partiality or bias.” Several courts have held, as we now hold, that representation of a parent corporation is likely to affect impartiality or may create an appearance of partiality in the lawyer’s representation of or dealings with a subsidiary.
E.g., Schlossberg v. State Bar Grievance Bd.,
Conrad therefore had a duty under the NASD Code to make a reasonable effort to inform himself of his firm’s representation of Pru-Baehe’s parent. Conrad did nothing to fulfill that duty. Thus, though he lacked actual knowledge, he had constructive knowledge of his firm’s previous representation of Prudential Insurance Co. Given Conrad’s constructive knowledge and the presence of the conflict, Conrad’s failure to inform the parties to the arbitration resulted in a reasonable impression of partiality under
Commonwealth Coatings. See Close,
Conrad’s evident partiality warrants vacatur of the arbitration award in this case. A finding of evident partiality in one arbitrator generally requires vacatur of the arbitration award. As stated in
Wheeler v. St. Joseph Hospital,
CONCLUSION
For these reasons, we REVERSE the judgment of the district court and VACATE
*1050
the arbitration award. Given our disposition, we decline to examine whether Conrad or the panel exceeded arbitral powers or whether
Rogers v. Schering Corp.,
Notes
. Appellants also discovered various facts concerning a relationship between Yamasaki and MacMillan which existed prior to the arbitration. In view of our disposition, however, we express no opinion on whether these facts or the failure to disclose them created evident partiality or caused Yamasaki and MacMillan to exceed their authority.
. Section 10(a)(2) of title 9 U.S.C. provides in relevant part, "In any of the. following cases the ... district court ... may make an order vacating [an arbitration] award upon application of any party to the arbitration— ... [w]here there was evident partiality ... in the arbitrators_"
. Conrad admitted that had he known of his firm's previous representation of Prudential Insurance Co., he would have disclosed it.
