Shareholders are angry that directors rejected Microsoft's bid to buy the firm
Yahoo has postponed its annual meeting after disgruntled investor Carl Icahn threatened to launch a battle to oust the board.
Mr Icahn opposes Yahoo's rejection of a takeover by Microsoft and plans to put forward his own slate of directors for shareholders to vote on.
Yahoo postponed the meeting, scheduled for 3 July, to an unspecified date later that month.
Yahoo snubbed Microsoft's offer to buy it in a deal worth $47.5bn (£24.1bn).
Microsoft abandoned its $33-a-share bid at the beginning of May but says it is now in talks with Yahoo about an alternative transaction, though no details have been provided.
Yahoo boss Jerry Yang is under pressure to win over investors.
The company's chairman Roy Bostock has criticised Mr Icahn's aggressive approach and rejected his claims that the board had acted "irrationally" in its dealing with Microsoft.
Yahoo made the postponement in a filing with the financial regulator, the Securities and Exchange Commission.