Four London law firms were among 34 practices from around the world that met last week in Madrid to launch an international network of lawyers acting for the alleged victims of the Madoff scandal.

Bristows, Edwin Coe, Rawlings Giles and Speechlys have joined the group, which has members in 20 countries, to exchange information and discuss tactics as they prepare legal challenges arising from the alleged $50bn Ponzi fraud.

The alliance, formed by Spanish firm Cremades & Calvo-Sotelo, is thought to be the first created as a response to a ­specific piece of global litigation. Its aims include collaborating to promote settlements and ­amalgamating as many alleged ­victims as possible to increase bargaining power.

Edwin Coe litigation head David Greene said it would help lawyers decide what kind of claims to bring and where – Germany, for example, has some favourable rules of court, such as over the burden of proof. The cases will in the main be negligence claims against intermediaries who advised on investing in the Madoff funds, he said.

Speechlys partner Nick Gibbons explained that the cases will be ‘all about due diligence’ and there are ‘a number of links in the chain’ – for example, a trust company which relied on another intermediary’s advice to invest could be sued by an investor; the trust company could also have an action.

He said the alliance would be a ‘very useful forum for sharing ideas and experiences’, and being in the same room as other London solicitors would not cause a problem. ‘Cooperation is now the name of the game... Everyone’s got their own clients already and there are too many [alleged] victims for any one firm to deal with.’

Gibbons added that his impression from the Madrid meeting was that the lawyers ‘are conscientious, genuine people trying to help their clients’.

Greene said the same approach may also be taken with investors who lost out over the alleged Ponzi scheme run by Allen Stanford.