Google overtakes Apple as world's most valuable listed company

Revenue spike sees tech firm's parent company, Alphabet, valued at $568bn - surpassing Apple's valuation of $535bn

Google has become the world's most valuable listed company after announcing that its global revenues rose 13% to $75bn (52bn) last year, and the group's tax rate fell to just 17%.

The group took a record $1.9bn of revenues from its UK customers for the last three months of 2015, up 16% on 2014 - and all routed through its controversial tax structure in Ireland. But for the impact of the pound weakening against the dollar, UK revenues would have been up 20%.