Yahoo rejected Microsoft's latest proposal, which sources briefed on the subject said included an offer to buy 16 percent of Yahoo for $35 per share, plus to buy its search business.
Yahoo simply said that an alternative Microsoft proposal to buy only its search business did not fit into its plan to grow search and display advertising.
Microsoft's offer for a minority stake was at a premium per share to its early May offer to buy the entire company for $47.5 billion, or $33 per share.
Microsoft, which said it was still open to an alternative deal, had hoped a Yahoo deal would accelerate its ability to capitalize on Web advertising growth and compete with Google, which is increasingly fighting for the same Internet audience.
Yahoo said on Thursday that Microsoft had made it clear in a meeting on June 8 that it was no longer interested in buying the company outright, even at the $33 per share price Microsoft had most recently proposed.
That may not appease Yahoo shareholders--including billionaire Carl Icahn--who have been pressuring Yahoo to reach a deal with Microsoft. Icahn has called for Chief Executive Jerry Yang to be ousted.