Ebay on Monday conceded that its controversial acquisition of the internet telephone service Skype had fallen well short of its hopes, writing down the value of its investment in the company by $1.43bn (£695m), or nearly 50 per cent.

At the same time, Niklas Zennstrom, one of the founders of Skype, quit as the unit’s chief executive after missing out on a pay-day that could have earned him and a handful of other shareholders an extra $1.2bn.