AOL to buy Huffington Post for $315m

AOL, the US internet company, is making a big bet on the viability of free online content by agreeing to buy the Huffington Post, the left-leaning web operation started by Arianna Huffington, for $315m.

The deal, which was announced late on Sunday night, is the latest and most significant step AOL has taken to becoming a serious player in advertising-supported internet content.