BRUSSELS (Reuters) -Apple, Alphabet's Google and Meta Platforms will be investigated for potential breaches of the Digital Markets Act, EU antitrust regulators said on Monday, a move that could lead to hefty fines for the companies.

The law, effective from March 7, requires six gatekeepers - which provide services like search engines, social networks and chat apps used by other businesses - to comply with guidance to ensure a level playing field for their rivals and to give users more choices.