The Week: City News - Facebook valued at $15bn

Microsoft has paid $240 million for a 1.6 per cent stake in Facebook, valuing the social networking business, which has yet to turn a profit, at $15 billion.

The software giant has also struck an exclusive deal to sell ads on all international versions of the site, although it is not known if the agreement also covers sponsored search listings. Membership of Facebook grew by 6 per cent last month, compared with just 1 per cent growth for the NewsCorp-owned MySpace.