Britain's competition regulator said it plans to designate Apple and Google with so-called strategic market status for their role in mobile ecosystems, as it steps up scrutiny of what it has described as their duopoly.

Apple Inc. and Google’s Android were earmarked by the UK’s antitrust watchdog for a raft of new rules targeting their power in mobile ecosystems, a market almost completely dominated by the US giants.

Apple and Google face new rules governing how they run their smartphone software and app stores in the UK, as Britain’s antitrust agency looks to impose new European-style controls on the Big Tech companies.