US firm Dorsey & Whitney is advising Watchstone Group – the UK company formerly known as Quindell – on a £637m claim brought against it by Australian-listed firm Slater and Gordon.

The claim relates to Slater's 2015 acquisition of Quindell's professional services arm. The Australian firm, which saw its share price collapse and losses balloon following the purchase, has alleged fraudulent misrepresentation in connection with the deal.

Dorsey's role was confirmed in an announcement to the London Stock Exchange yesterday (20 September), in which Watchstone also stated that its legal costs provision for the claim have more than tripled from £1m to £3.5m.

Watchstone, under its former identity of Quindell, is a longstanding client of HSF. Cogman previously advised it on two investigations in 2015 – one by the Financial Conduct Authority in relation to its public statements about its financial accounts, and another by the Serious Fraud Office into its past business and accounting practices.

It is understood Dorsey London disputes partners Tim Maloney and Matthew Blower are advising.

CMS Cameron McKenna Nabarro Olswang is advising Slaters, with disputes partner Jeremy Mash in the lead.

Slaters – which in 2007 became the first ever law firm to go public when it listed on the Australian Stock Exchange – entered the UK market in 2012 with the £53.8m takeover of Russell Jones & Walker. This was followed by a flurry of acquisitions, culminating in the £637m Quindell acquisition in 2015.

However, the firm has since been beset by difficulties and last month it was announced that Slaters' UK business is to be divided from its Australian parent into a holding company owned by the indebted firm's senior lenders.

Earlier this month, Legal Week reported that Slaters had moved more than 40 of its UK partners out of its partnership in the last financial year, amid fears among partners that they could lose their capital if the firm went into administration. Insurance firm BLM has confirmed that it has held talks to acquire the firm's UK business legal services team.

Dorsey declined to comment.