AOL and several private equity firms are in talks to possibly buy Yahoo Inc., people familiar with the deal said late Wednesday. The talks do not include Yahoo, which has hired Goldman Sachs to help defend against possible takeover approaches, sources say. If successful, a merger could bring together the two early behemoths of the Internet, whose stars have gradually faded. According to sources, Silver Lake Partners and Blackstone Group are among the firms that expressed interest, though neither commented on any possible deal. Since AOL is worth $2.68 billion—far less than Yahoo’s $20.57 billion market value—the deal would have to involve several partners or scenarios. And indeed, a combined AOL-Yahoo would pose a larger threat to Google, which so far, has dominated the industry in advertising.