LONDON — Amazon, seeking to resolve two European Union antitrust investigations, has promised to treat third-party merchants on its website fairly, the bloc’s competition watchdog said today.

The U.S. online retail giant offered to make a number of commitments to ease competition concerns, and the European Commission, the 27-nation bloc’s top antitrust enforcer, said it will now seek feedback on them from “interested parties.”

The commission launched an investigation four years ago over concerns Amazon was using data from merchants selling products on its platform to gain an unfair advantage over them.

It also opened a separate investigation into whether Amazon favors its own retail business and merchants that use its logistics and delivery system over other sellers.

The investigations are part of the bloc’s wider efforts to curb the power of big technology companies.

Amazon said it has “serious concerns” that new EU digital regulations are “unfairly targeting Amazon and a few other U.S. companies” and disagrees with several of the commission’s conclusions.

But the company added that it has “engaged constructively with the commission to address their concerns and preserve our ability to serve European customers and the more than 185,000 European small and medium-sized businesses selling through our stores.”

Amazon had faced a possible fine of up to 10% of its annual worldwide revenue, which could have amounted to billions of dollars.

Britain’s competition watchdog opened a similar probe into Amazon last week, looking into concerns that the online retailer is abusing its dominance to undermine rivals.