A European Union court has cleared an earlier decision by EU regulators to green-light Microsoft’s $8.5 billion takeover of Skype in 2011, following a legal challenge by Cisco.

Cisco had argued that the Microsoft-Skype deal would be anti-competitive and that the EC was mistaken in approving the deal without gaining concessions from Microsoft.

However, the EU’s General Court argued that Microsoft’s traditional dominance in the PC world had not extended into the mobile-dominated present.

The consumer communications sector, the court said, is “a recent and fast-growing sector characterised by short innovation cycles in which large market shares may turn out to be ephemeral”.

“Moreover, Microsoft, which has traditionally held a very large share of PC software market, is less present on new operating devices, such as tablets and smartphones, which are becoming increasingly important on the consumer communications market,” it said.

Cisco filed its complaint alongside Messagenet, an Italian rival to Skype.