Microsoft Corp. and an Amazon Inc. unit’s dominance in the cloud services market must face an antitrust investigation under the UK’s new rules for digital markets, the country’s watchdog said after 21 month-long investigation.

Amazon and Microsoft's dominant position in cloud computing is having an adverse effect on competition, exacerbated by technical and commercial barriers to switching, an inquiry group from Britain's antitrust regulator said.

Microsoft’s software licensing terms are harming competition in the cloud computing market, an investigation ordered by the UK antitrust regulator has found, driving up costs for its Big Tech rivals.