The blogosphere is awash with rumours of merger talks between Microsoft and Yahoo! as the two companies seek to challenge the mighty Google.

The source of the speculation is an article in the New York Post, which claims that Microsoft is the driving force behind the possible deal and that Yahoo!’s price could be around $50bn (£25bn).

A wave of online ad acquisitions are expected to take place in the wake of Google’s acquisition of Doubleclick last month, including Yahoo!’s recent purchase of ad exchange Right Media and expectations of a buyout of ad tech firm 24/7 Real Media.

The deal would allow the companies to close the gap on Google in the search market, as well as giving the pair a massive combined online audience. 

But this is not the first time that a merger between the two has been rumoured – there were reports that the pair were in talks this time last year.