BRUSSELS—Draft EU rules to curb the power of Amazon, Apple, Alphabet unit Google and Facebook should also tackle providers of cloud computing services for possible anti-competitive practices, a study said on Tuesday. The report comes amid concerns that some EU lawmakers who are reviewing the Digital Markets Act (DMA) proposed by EU antitrust chief Margrethe Vestager may be lenient towards cloud computing companies. Amazon’s Amazon Web Services was the leading provider in the second quarter, followed by Microsoft Azure and Google Cloud, market research company Statista found. Others include IBM Cloud, Alibaba Cloud, Salesforce and Oracle. Frederic Jenny, chairman of the Organisation for Economic Cooperation and Development’s Competition Committee, put together the study, in his personal capacity, for trade body Cloud Infrastructure Services Providers in Europe (CISPE). The new EU rules should also cover software licensing, the report said, with respondents citing unfair terms imposed by some of the big …