Yahoo Inc. failed to agree to an acquisition deal with Microsoft Corp. by Saturday, the deadline Microsoft had set for wrapping up negotiations. Now Microsoft must decide whether to pursue a hostile takeover via a proxy fight or to drop the bid and seek other acquisition alternatives.

All along, Microsoft's management had strongly indicated that it would pursue Yahoo via all available options, including the hostile route of ousting the current board by proposing its own slate of director candidates at the next Yahoo shareholders' meeting.

But Microsoft CEO Steve Ballmer and Chief Financial Officer Chris Liddell softened that stance in public comments last week, saying that giving up on the acquisition would also be an option.

On Sunday, Yahoo declined to comment. Microsoft responded by pointing to comments Liddell made on Thursday during Microsoft's earnings announcement. "Unless we make progress with Yahoo towards an agreement by this weekend, we will reconsider our alternatives. We will provide updates as appropriate next week ... these alternatives clearly including taking an offer to the Yahoo shareholders, or to withdraw our proposal and focus on other opportunities, both organic and inorganic," Liddell said then.

Citing anonymous sources, The Wall Street Journal reported Sunday that Microsoft, Yahoo and their advisers have held talks in recent weeks but didn't achieve enough progress to hammer out a deal by Saturday. The process has clearly been frustrating for Microsoft executives, who have maintained that their offer is fair and that they don't see a reason to revise it. Ballmer and his team have shown signs of getting impatient with the slow progress, which is not surprising considering Microsoft's urgent desire to boost its underperforming Internet business and to better compete against Google Inc.