Experts are claiming that a business partnership between Google and Yahoo! could be more heavily criticised by US and EU competition regulators than a merger between Microsoft and Yahoo!. Aaron Edlin, who teaches law and economics at the University of California at Berkeley said:

The Justice Department would certainly want to take a serious look at that because it would mean that a firm that would want to take advertisements or to place advertisements (online) would have only one place to go.

Google was the top search engine in February, accounting for 59.2% of US web searches, with Yahoo! and Microsoft lagging behind on 21.6% and 9.6% respectively. Microsoft has proposed a $42 billion takeover bid for Yahoo! in an attempt to combat this dominance, although Yahoo! has so far refused to accept the deal.