CMS Cameron McKenna has become the latest law firm to pick up an advisory role relating to the €136m (£120m) negligence claim against Linklaters by Credit Suisse.

The City firm has been instructed to advise Italian independent Gianni Origoni Grippo & Partners, which faces a counter-claim by Linklaters stemming from advice the two firms gave on a bond deal with Italian food company Parmalat in 2001.

Camerons' City insurance partner Peter Maguire is understood to be likely to take the lead role for Gianni, although the firm's appointment still needs to be approved by Gianni's insurance company.

Camerons' appointment is the latest development in the case that started when Credit Suisse filed a claim against Linklaters in March, relating to advice Linklaters gave the bank on the deal around a decade ago. The advice was given two years before Parmalat went into administration in 2003 by Linklaters capital markets partner Simon Firth, who took advice from then Italian alliance partner Gianni.

Following Credit Suisse's claim, Linklaters filed its own negligence claims in the Admiralty and Commercial division of the High Court later in March against Gianni, along with a number of its individuals.

The magic circle firm has turned to Slaughter and May, where dispute resolution partner Deborah Finkler is leading, alongside Italian independent Bonelli Erede Pappalardo. Clyde & Co is advising Linklaters' insurers in relation to both claims.

Bonelli founding partner Sergio Erede's was awarded an 18-month suspended sentence awarded in December last year for negligence in relation to the collapse of Parmalat. He was a former board member of the company.