Alphabet (NASDAQ:GOOG) shares fell more than 2% in early Wednesday trading after Google was hit with a multi-billion-pound class action lawsuit in the U.K., accusing the tech giant of abusing its dominance in the online search market.

The 5 billion (roughly $6.6 billion) claim, filed on behalf of British businesses that have used Google's search advertising services since 2011, alleges that Google leveraged its "near-total control" to inflate ad prices by limiting competition in the sector.

The legal complaint, led by competition law scholar Or Brook and represented by Geradin Partners, claims Google paid Apple (AAPL) billions to remain the default search engine on Safari. It also says the company struck deals with Android phone makers to pre-install Google Search and Chrome, further locking out rivals.

Brook said U.K. businesses have had "almost no choice" but to rely on Google for online ads and argued the company "overcharged" advertisers through anti-competitive behavior, according to a Wednesday CNBC report.

The lawsuit adds to growing global scrutiny over Google's market dominance and follows similar regulatory pushback in the U.S. and EU.