SAN FRANCISCO -- Yahoo urged shareholders Friday to shun corporate raider Carl Icahn and rebuff his efforts to replace board members with people amenable to a takeover by US software giant Microsoft.

"We do not believe the election of the Icahn Entities nominees to our board of directors is in the best interests of our stockholders," Yahoo said in a filing with the US Securities and Exchange Commission.

"Our board of directors urges you not to sign or return any proxy card sent to you by the Icahn Entities."

Icahn filed paperwork with the SEC earlier in the week saying that through various entities he owns 4.28 percent of Yahoo's common stock and is lobbying shareholders to back him in replacing the board of directors.

Icahn said in his filing that he and allies in overthrowing Yahoo's board "urge you not to sign any proxy card sent to you by Yahoo," but to instead use the stock holder voter cards to elect him and his nine fellow candidates.

Yahoo said Friday it was delaying a July 3 shareholders meeting in an attempt to stave off a showdown with the billionaire corporate raider.

Icahn has reportedly bought 59 million shares of Yahoo stock and plans to oust board members he accuses of botching recent takeover talks with Microsoft.

Microsoft walked away from the bargaining table after Yahoo's board spurned the US software giant's offer of nearly $50 billion (32 billion euros) on the grounds they feel it undervalues Yahoo.