Google is said to be exploring a run at Yahoo with private equity partners as the club of potential bidders for the Internet company expands.A report in the Wall Street Journal over the weekend that Google is kicking the tires came days after news that Microsoft and another set of buyout firms were considering a deal. While Yahoo may be struggling, it seems neither Microsoft nor Google want to cede such prime online real estate to the other. Yahoo and Microsoft already have a search deal in place that was just extended through 2013. Yahoo’s market value stood at $20.3 billion as of Friday. The stock has been buoyed by deal speculation. Both Microsoft and Google, as part of larger bidding groups, would contribute only a portion of the purchase price but become key strategic partners. Yahoo’s interim chief executive Tim Morse said last week that the board was continuing to review its strategic options, while strengthening its sales force and core businesses. The famous brand has been struggling with competition from Facebook and other sites. Its shares closed down 0.37% at $16.12 Friday.