FILE PHOTO: The logos of Amazon, Apple, Facebook and Google are seen in a combination photo from Reuters files. REUTERS/File Photo

BRUSSELS (Reuters) - EU antitrust regulators are considering taking a tougher line against tech giants by forcing them to do more to ensure a level playing field, a senior European Commission official said on Tuesday, a move which could affect Facebook, Amazon, Apple and Google.

The four U.S. tech companies are currently in EU competition enforcers’ crosshairs, with rivals complaining about being shut out of key markets.

The Commission has traditionally ordered companies to halt anti-competitive practices.

This may not be enough, especially in digital markets, said Cecilio Madero Villarejo, acting director-general at the Commission’s competition division.

“In fast-moving markets there is a risk that this would take too long to implement and be too difficult to monitor,” he told a CRA conference.

“Therefore in particular in these markets, fast moving markets, we may design more prescriptive and possibly restorative remedies in order to ensure that conditions for effective competition will be fully restored,” Madero said, without elaborating.

On Monday European Competition Commissioner Margrethe Vestager said with hindsight she would have taken a different line with Google despite imposing fines of more than 8 billion euros on the company after a decade-long investigation.

“If I knew what I know now about Google, I would be bolder,” Vestager told a Politico conference.