The world’s biggest software maker, Microsoft Corp, announced today its proposal to buy Yahoo Inc for $44.6 in cash and stocks. The surprise offer was timely as Yahoo’s stock slipped to a four-year low earlier this week. The offer represents a 62 percent premium above the closing price of Yahoo! common stock on Jan. 31, 2008. The convergence would offer a credible alternative for consumers, advertisers, and publishers as the market is currently dominated by Google.