Microsoft, positioning itself for a new run for Yahoo’s web search business, has approached other media companies in recent days about joining it in a deal that would effectively lead to Yahoo’s breakup, reports the WSJ. Microsoft has held discussions with Time Warner and News Corp, among others, say people involved in the talks. In the past, Microsoft has floated an arrangement under which it would acquire Yahoo’s search business and another partner, such as News Corp’s MySpace or Time Warner’s AOL, would combine forces with what remained of Yahoo. The FT meanwhile reports that Microsoft on Wednesday announced the purchase – reportedly for about $100m - of Powerset, a Silicon Valley company that has developed a promising, and controversial, new internet search tool.