Europe’s competition watchdog has opened a full inquiry into the datafeed supply agreements between Thomson Reuters and its trading customers. The European Commission suspects the agreements might “lock” users, such as large banking groups, into working with the news and financial data company and breach antitrust rules.

The Commission said on Tuesday it was concerned Thomson Reuters might have a dominant position in the supply of real-time market data, such as stock market prices, and abuse this through restrictions in contracts with customers.