Expedia is not only trying to put pressure on Google in the US through the FairSearch campaign, but has now opened a second front in Europe over allegations of a "violation" of competition law.
Expedia Inc filed the complaint with the European Commission on Friday last week, full details of which have yet to be disclosed.
The online travel agency says the complaint outlines "specific business and search practices" from Google that it alleges are at odds against European Union "competition and consumer protection laws".
Expedia is urging the Commission for "strong action" against what it claims are practices which impact the wider competitive landscape as well as consumers.
This is needed to "restore a fair and competitive marketplace in online search that respects consumers' rights", says Expedia senior vice president of government affairs, Brent Thompson.
Although Google's focus on the travel sector - through the launch Google Flight Search in the US with expected expansion overseas and and the continued roll-out Hotel Finder - is not mentioned specifically, Expedia probably has more than one eye on how the situation develops and the search giant's influence over consumer travel search grows.
Google, in an emailed statement, says:

"We haven't seen the complaint yet, but we’ve been working to explain how our business works, cooperating with the European Commission since this investigation began. Because there’s always room for improvement, we're happy to discuss any concerns the Commission might have."
Expedia joins the likes of Microsoft with its concerns - and subsequent complaints - over the dominance of Google in cross-vertical search.
The latest development comes just a month after US anti-Google lobbying group FairSearch (which counts Expedia and Microsoft as members, alongside Kayak and TripAdvisor) launched official operations in Europe under the guidance of Brussels-based lawyer Thomas Vinje, a high profile figure who ironically had previously spent the best part of 16 years fighting against Microsoft over accusations of anticompetitive practices in Europe.
NB:European flag image via Shutterstock.