Microsoft called the Yahoo board of directors' rejection of the software company's $44.6 billion offer "unfortunate," and suggested it will press to get the deal done.
"It is unfortunate that Yahoo! has not embraced our full and fair proposal to combine our companies," Microsoft said in a statement issued almost nine hours after Yahoo posted its rejection statement on its site Feb. 11.
"Based on conversations with stakeholders of both companies, we are confident that moving forward promptly to consummate a transaction is in the best interests of all parties."
Microsoft said the combination of the two rivals would enable it to better compete with Google in the market for Internet services, where Google lurks as the top earner for search and ad dollars generated from such services.
Yahoo said earlier that Microsoft's offer "substantially undervalues" Yahoo's worth when considering the company's global brand, technology assets and operating cash flow.
Financial analysts have said Yahoo is more likely holding out for a higher bid-in the $40 per share or greater range-than it is trying to fight Microsoft full out.
Microsoft isn't budging, suggesting that it will fight to acquire the company, though without specifying how.
"Microsoft reserves the right to pursue all necessary steps to ensure that Yahoo's shareholders are provided with the opportunity to realize the value inherent in our proposal," the company said.
With that statement in mind, IDC analyst Karsten Weide told eWEEK that Microsoft's next step is to offer a sweeter bid, but is unlikely to offer the $40 many believe Yahoo is looking for.
In parallel, Microsoft will seek out the largest Yahoo shareholders to convince them of the deal's value and ask them to press Yahoo's board to take a deal.
Microsoft offered to buy Yahoo Feb. 1 for $31 per share, a 62 percent premium over Yahoo's then closing price from Jan. 31.
Yahoo is reportedly looking to Google and AOL to strike some sort of deal that would help it fend off Microsoft while remaining a viable business.