"No thanks, Rupert!" Microsoft Corp says it wants to stick with its original takeover offer for Yahoo Inc, but is not ruling out News Corp joining its bid or other options, a source close to the company said on Friday. Separately, News Corp is rumored to continue to talk directly with Yahoo on reaching a deal without Microsoft. Fighting for a technical knock out, Microsoft has delivered what many define as the final ultimatum to Yahoo to either come to the bargaining table or face a proxy contest to unseat their board of directors. The Yahooligans have parried with a letter of their own, and a deft counterpunch. First, rebutting that the initial offer undervalues Yahoo's worth and then landing a stunning shot by announcing a two-week pilot experiment with Google AdSense for Search ads that will be seen alongside 3% of search results on Yahoo's website.