BRUSSELS, March 21 (Reuters) - Apple ( AAPL ), Meta

Platforms ( META ) and Alphabet's Google are set to be

investigated for potential violations of the European Union's

Digital Markets Act (DMA) that could lead to hefty fines by the

end of the year, according to people with direct knowledge of

the matter.

The European Commission will likely announce the

investigations, either at the same time or one after the other

rapidly, in the coming days and issue decisions before EU

antitrust chief Margrethe Vestager's term ends in November, they

said.

DMA breaches could cost the companies as much as 10% of

their global annual turnover. The landmark EU tech rule requires

companies to give users and rivals more choices to ensure a

level playing field.

The Commission declined to comment. Apple ( AAPL ), Meta and Google

did not immediately respond to requests for comment.

Earlier this week, Vestager in an interview told Reuters

Apple and Meta's new fees for their services may hinder users

from enjoying the benefits of the DMA, and that this was going

to be part of any investigation.

She also singled out tactics used by some companies to

disparage rival products or services to discourage users

switching to them, saying it was unwise for companies to do so.

Vestager also said she wanted to speed up any DMA

investigations, aiming to get decisions out preferably in six

months so that users and apps developers can see the fruits of

the new rules soon. Traditional EU antitrust probes in contrast

take years.

Rivals of the three companies have shared frustrations with

the EU competition enforcer, saying measures announced by the

companies to re-wire their core platform services are

inadequate.

The DMA requires the three companies, as well as Microsoft ( MSFT )

, Amazon.com ( AMZN ) and TikTok owner ByteDance to

allow users to remove any pre-installed software or app if they

want, and to get users' consent to use their data across their

various services or for personalised ads.

The companies are not allowed to favour their services or

products over rivals on their platforms.

Bloomberg was the first to report the imminent DMA

investigations into Apple ( AAPL ), Meta and Google.