While some Yahoo investors hoped it could wrest a price of $35 per share from Microsoft, a dissident shareholder said he would challenge Yang and the board over the collapse of talks.
"Shareholders didn't even get a chance to vote on the deal, but the board negotiated on our behalf and not in good faith," said Eric Jackson, who leads a group of investors who collectively own 2 million Yahoo shares.
He said he would urge shareholders to withhold votes from the company's directors this year.
Bernstein's Lindsay estimates Yahoo could be worth up to $35 per share with a Google deal, and even $37 with more job cuts, but that drops to $25 per share if no partnerships are in the offing.
Yahoo has conducted tests with Google to outsource some of its search listings to its arch-rival. It has also held talks in tandem with AOL and Rupert Murdoch's News Corp.
A source familiar with the matter said on Sunday that the News Corp talks had cooled in recent weeks.
"It increasingly appears like Yahoo will pursue a Google search partnership," said Moran, who said he still favored a Microsoft buyout. "Given Google's position (in the market), a partnership with them cedes control and limits the long-term value creation for Yahoo."