Just 0.2% of Facebook flogged for $133m

Ad firm Interpublic has sold half its stake in Facebook for $133m.

The firm's stake was 0.4 per cent, so the sale gives an apparent value for the whole social network of $66.5bn.

The deal was done back in 2006, when Facebook needed revenue and respect. Interpublic agreed to spend $10m of its clients' money on advertising on the site and in exchange was allowed to buy a 0.4 per cent stake for less than $5m, the FT reports. Interpublic brands include McCann Erickson and Lowe + Partners; the firm turned over $6.5m last year.

Interpublic's statement did not reveal who had bought the stake but the pink paper said it was not Facebook itself – which has first refusal in such deals.

The ad company said it would pocket $132m from the deal.

Chief executive Michael I Roth said: "Interpublic formed a strategic relationship with Facebook in 2006 ... Facebook has since become a part of daily life for hundreds of millions of people around the world. Its ubiquity has meant the strategic value of our initial investment has moderated, while the financial value of that stake appreciated significantly."

Interpublic's full statement is here. The company will use the cash to buy back its own shares. ®