The company said in a filing with the US Security and Exchange Commission (SEC) that it would push back a 3 July meeting to a date that has yet to be determined.
Yahoo told the SEC that the meeting would most likely be rescheduled for late July.
The company credited the delay to the looming threat of a hostile boardroom takeover by billionaire investor Carl Icahn.
Icahn told Yahoo last week that he would commence buying more Yahoo stock, and push to have the board replaced with 10 new members who would favour a deal with Microsoft.
The investor revolt began after talks with Microsoft over a possible acquisition fell through.
Microsoft first issued the proposal in early January. The value of the deal climbed as high as US$47.5 billion before Microsoft finally gave up its pursuit as Yahoo moved closer to securing an advertising deal with Google.
Analysts initially praised Microsoft's decision to back away from the acquisition efforts, citing major corporate differences and a possible employee exodus to rival companies.
A group of investors, led by Icahn, was significantly less pleased with the development, and a hostile takeover bid was launched.
When Yahoo's board does eventually meet to discuss the matter, it will be short of one director after Edward Kozel resigned his position on 20 May.
Yahoo did not credit Kozel's departure to the Icahn effect. The company told the SEC that Kozel "wanted to spend more time with his family" and had made his intentions known in February.
Yahoo will not immediately replace Kozel and will instead go forward with a nine-member board.
Yahoo postpones annual meeting
By Shaun Nichols on May 26, 2008 7:43AM