Clifford Chance (CC), Cleary Gottlieb Steen & Hamilton and Covington & Burling are advising as the European Union prepares to come to a decision on the first stage of a three-pronged probe into the search group's practices.

EU officials are reportedly poised to fine the search engine more than €1bn (£870m) for abusing its search market dominance by steering European consumers to its Google Shopping service.

The three law firms were first called up in 2015, when Google was accused of anti-competitive behaviour by the European Commission.

Cleary is representing Google with a team led by London-based competition partner Maurits Dolmans and Brussels-based counterparts Thomas Graf and Robbert Snelders.

Meanwhile, CC is advising the complainants on the case with a team led by partner Thomas Vinje, who is legal counsel and spokesman for lobby group FairSearch Europe, alongside antitrust partner Dieter Paemen.

The regulator has not formally disclosed the names of complainants, although a number of companies have gone public with their complaints. These include French legal search engine eJustice and British price comparison site Foundem.

It is not yet known which companies CC is acting for.

Covington is also advising the complainants. The firm confirmed it is acting for travel websites Expedia, TripAdvisor and trivago, with a team in Brussels led by partner Miranda Cole. ‎

Previously, the firm also acted for Microsoft on the case.

The three firms are also involved in a second, related, investigation looking at whether Google used its dominant position to prevent third-party websites from displaying search advertisements from its competitors.

The third case examines whether Google's Android mobile operating system, as well as applications and services for smartphones and tablets, have breached EU antitrust rules by stifling rival mobile operating systems.

A&O is advising Google on the Android case alongside Cleary, with a Brussels-based team led by competition partner Juergen Schindler alongside fellow competition partners Dirk Arts and Ellen Braun.

CC is also advising the complainants on this case.