A pair of recent filings in US litigation over alleged foreign exchange rate manipulation has revealed a dispute that pits Quinn Emanuel Urquhart & Sullivan against plaintiffs firms Hausfeld and Scott + Scott.

The dispute, which revolves around foreign exchange rate antitrust litigation, takes on added import because all three firms are eyeing key roles in similar litigation in Europe.

The spat between the firms stems from a memorandum that Quinn Emanuel crafted in late 2016 and early 2017 about the foreign exchange rate antitrust litigation, and later sent to plaintiffs firm Bernstein Liebhard and multiple institutional investors.

Hausfeld and Scott + Scott serve as co-lead counsel in the US for investor plaintiffs in the foreign exchange rate litigation, while Quinn Emanuel in 2014 lost a bid for a lead plaintiffs counsel role.

The underlying antitrust suit alleges a widespread scheme involving many of the world's largest banks. They are accused of manipulating the foreign exchange market, which averages some $5trn in trading per day. A number of the bank defendants, including JPMorgan and Barclays, have settled the US litigation for a total of more than $2bn, although claims remain pending against several others, such as Credit Suisse and Deutsche Bank.

On 12 May, Hausfeld and Scott + Scott wrote in a brief that the memo Quinn Emanuel initially crafted and sent out contained misleading information about the settlement and deadlines to opt out of the class to pursue individual claims. In light of those communications, Scott + Scott and Hausfeld wrote, US District Judge Lorna Schofield in Manhattan should force Quinn Emanuel and Bernstein to turn over the names of the institutional investors they contacted.

"Plaintiffs have serious concerns that the communications could confuse class members or convince them to compromise their rights under the settlements based on erroneous information," the brief said.

But Quinn Emanuel, which responded on Monday, said the bid by Scott + Scott and Hausfeld was a ruse and that the information they asked for would be confidential under lawyer-client privilege. Quinn Emanuel accused Scott + Scott and Hausfeld of trying to obtain the information to give the firms a leg up in competing for a key role in parallel foreign exchange litigation expected to start soon in Europe.

"The decision whether or not to opt out is a particularly significant one for a number of large and sophisticated class members who suffered significant damages arising out of the FX cartel in the US… and overseas," Quinn Emanuel wrote in its brief. "Class counsel… have an obvious self-interest in preventing such entities from opting out and also in persuading these entities to engage them, rather than Quinn Emanuel or another law firm, in Europe."

Scott + Scott's Christopher Burke declined on Wednesday to comment while the issue is pending in court, and Michael Hausfeld of Hausfeld did not immediately respond to an email.

Both firms have previously cited the forex case as a driving force behind their efforts to expand and pursue antitrust cases across the Atlantic. Recent plaintiff-friendly reforms in the UK and the European Union have made those markets more attractive to US-based plaintiffs firms.

Daniel Brockett of Quinn Emanuel on Wednesday confirmed that his firm is actively competing against Scott + Scott and Hausfeld for potential European claims related to alleged forex market manipulation.

"We have really strong competition lawyers in our London office and I think we have said in our papers here that that's something that we're doing," he said. "We're actively advising potential clients in Europe."

Schofield has scheduled a hearing for 5 June on Scott + Scott and Hausfeld's motion to compel. The two firms have a deadline of 23 May to file a reply brief responding to the opposition brief that Quinn Emanuel filed on Monday.