EU and British regulators said on Friday that they were beginning separate antitrust inquiries into Facebook, broadening their efforts to rein in the world’s largest technology companies.

The investigations by the European Commission, the executive arm of the 27-nation bloc, and Britain’s Competition and Markets Authority, take aim at a key business strategy used by Facebook and other large tech companies: to use their size and power in one area to enter others.

Amazon took its position as the largest online retailer to become a major player in video streaming. Apple leveraged the iPhone to be one of the world’s largest mobile payments with Apple Pay. Google parlayed its dominance as a search engine into many different areas.

The regulators said they would start formal investigations of Facebook Marketplace, an eBay-like service introduced in 2016 for users to buy and sell products.

Under scrutiny is whether Facebook’s cross-promotion of Marketplace to the more than two billion users of its main social network gave the company an unfair advantage over rivals in violation of EU competition laws.

Margrethe Vestager, the EU’s executive vice-president in charge of competition policy, said Friday that Facebook collects “vast troves of data” on the activities of its users, “enabling it to target specific customer groups.”

“We will look in detail at whether this data gives Facebook an undue competitive advantage in particular on the online classified ads sector,” she said in a statement, “where people buy and sell goods every day, and where Facebook also competes with companies from which it collects data”.

“In today’s digital economy, data should not be used in ways that distort competition,” she said.

In Britain, antitrust regulators are already investigating the company’s advertising practices. On Friday, the competition regulator said it was looking at Facebook Marketplace and Facebook Dating, a service introduced in Europe last year. The British regulator said it would work with the European Commission, though the investigations are independent of each other.

Facebook defended its business practices in a statement on Friday. “Marketplace and Dating offer people more choices and both products operate in a highly competitive environment with many large incumbents,” a representative of Facebook said. “We will continue to cooperate fully with the investigations to demonstrate that they are without merit.”

A preliminary investigation had already been underway, with the European Commission sending questions to Facebook’s rivals. Last year, Facebook sued the European Commission over demands made by regulators to turn over documents and data, saying the materials sought were overly broad and included highly sensitive information about employees. Facebook said it provided more than one million documents related to the Marketplace investigation.

The inquiry adds to the regulatory challenges Facebook is facing around the world. In December, the Federal Trade Commission announced antitrust charges against Facebook for illegally buying up smaller rivals to stamp out competition. Australian regulators have filed a similar suit. German antitrust regulators also brought charges against Facebook over data collection, a case now under appeal.

Since leaving the EU, the UK is ramping up its own efforts to regulate how tech firms use their size to enter new sectors and the problems that poses for regulations.

New York Times News Service