Microsoft Corp.'s unsolicited bid to buy Yahoo came two weeks ago, which was valued at US$44.6 billion at that time. However, Microsoft's price has tumbled 12.8 percent since then, dropping the value of the offer to $41 billion.

Yahoo turned down the offer and said it "substantially undervalues" the company's assets. It was said that last week Yahoo was in talks with News Corp. about a complex deal, in order to push its market value toward $50 billion. Yahoo also was reportedly discussing an advertising partnership with Google, according to an article on MediaInfoCenter.

Most analysts believe Microsoft will do whatever it takes to acquire Yahoo.

Microsoft has been investing aggressively in honing its own search engine and ad technology, but, like Yahoo, still cannot compete against Google, which dominates in U.S. search queries and related advertising revenue.

Analysts said Yahoo is expected to be valued at least at $40 per share, but Microsoft has held firm so far, claiming its original bid was "full and fair." Microsoft could possibly take the offer directly to Yahoo's shareholders, or to attempt a hostile takeover of Yahoo's board, AP reported.