BRUSSELS (Reuters) -U.S. technology firms including Amazon, Apple, Facebook, and Google face fines of up to 10% of annual turnover and could even be broken up under draft European Union rules announced on Tuesday aimed at curbing their powers. The rules are the most serious attempt by the 27-country bloc to rein in tech companies that control troves of data and online platforms relied on by thousands of companies and millions of Europeans for their work and social interactions. They show the European Commission’s frustration with its antitrust cases against the tech giants, notably Alphabet’s Google, which critics say have not addressed the problem. But they risk inflaming tensions with Washington, already irked by Brussels attempts to tax U.S. tech firms more. “It seems Europe is intent on punishing successful companies that have made deep investments in Europe’s economic growth and recovery,” Myron Brilliant, executive vice president of the U.S. Chamber of Commerce said in a statement. Regulatory scrutiny has been growing worldwide of tech giants following a string of scandals over privacy and misinformation, as well as complaints from some businesses that they abuse their market power. EU Internal Market Commissioner Thierry Breton dismissed suggestions the rules could be discriminatory. “Everybody is welcome in Europe. Our responsibility is to give direction, rules to protect what is important to us,” he told a news conference. One set of rules, the Digital Markets Act (DMA), targets so-called online gatekeepers - defined among other things as firms with more than 6.5 billion euros in annual European turnover in the last three years, 65 billion euros in market value and providing a core platform service in at least three EU countries. This sets out a list of dos - such as sharing certain kinds of data with rivals and regulators - and don’ts - among them a halt to favouring their own services on their platforms, and calls for fines of up to 10% of annual global turnover for firms that don’t comply, or a break-up order as a last resort. Gatekeepers will also be required to report merger bids to the authorities, a move aimed at preventing acquisitions to kill off rivals.