The move could lead to an antitrust investigation into their business practices. Microsoft, Amazon and Google, thanks to their ability to provide enterprise-scale computing and storage, are the biggest players in the massive cloud infrastructure market, which Ofcom (Britain's media watchdog) estimates to be worth between £4.5 billion ($5.6 billion) and £5.0 billion in 2021.

According to the regulator, Microsoft and Amazon's Amazon Web Services unit have a 60 to 70 percent market share, with Google accounting for 5 to 10 percent of the overall market share. In particular, Microsoft is allegedly using its strong position in software products to distort competition in cloud infrastructure.

Performance of Microsoft during last 5 years. (Source: Investing)