The apparent end of acquisition talks between Microsoft (NSDQ: MSFT) and Yahoo (NSDQ: YHOO) is “a shame” for the advertising industry, according to Sir Martin Sorrell, CEO of the WPP ad group. He told CNBC (via Reuters): “It was a shame ... that those negotiations failed. Maybe they’ll come back again. To have a balanced marketplace in the online search (market) I think is important.”

Google (NSDQ: GOOG) has previously spoken up about the concentration of advertising inventory in Google’s hands, including its DoubleClick acquisition - a fact he reckons could keep prices high. Adding a view from an industry much talked about during YHOO/MSFT talks, but little talked to, he said today: “What we’re looking for on behalf of our clients is more balance. WPP is currently investing in digital and China.