Google could be quietly bidding to acquire Yahoo by working through several private equity firms, says The Wall Street Journal. The report's just another twist in a tale that so far has linked a Yahoo deal to AOL, and Alibaba, and Microsoft. Why Google would seek a partnership to make a bid for the beleaguered search and media company isn't clear. What is certain's been in play since its board fired CEO Carol Bartz in September. Any deal involving Google and Yahoo is sure to get the attention of federal regulators because of anti-trust concerns. That aside, Yahoo could gain much from a deal with Google, beginning with its staying alive. And with a 700 million visitors each month and a going display-ad business, even a weakened Yahoo can bring a lot to the party. According to eMarketer, the company will generate $1.6 billion in ad revenue this year, behind Facebook's $2 billion -- but ahead of Google's $1.1 billion.