BRUSSELS (Reuters) -Apple ( AAPL ), Google and Microsoft ( MSFT ) have been asked by EU tech regulators about the measures they are taking to prevent their platforms being used for financial scams, underscoring Europe's concern about the cost of online fraud.

The EU is increasing its regulatory scrutiny of major U.S. technology companies via the Digital Services Act, landmark legislation that requires Big Tech to do more to tackle illegal and harmful content on their platforms.

"Today, we sent requests for information, under the DSA, to Apple ( AAPL ), Booking.com, Google and Microsoft ( MSFT ) on how they identify and manage risks related to financial scams," EU tech chief Henna Virkkunen wrote on X on Wednesday.

"Online fraud can start very easily nowadays, and too often results in financial losses for consumers," she added.

Such online scams, ranging from fake hotel listings and fraudulent banking apps to deepfakes of public figures promoting false investments, cost Europeans more than 4 billion euros ($4.7 billion) annually, Virkkunen said 

Regulators around the world have voiced concerns that the rise of AI could make consumers more vulnerable to scams such as phishing and fraudulent investment schemes.

($1 = 0.8512 euros)