SAN FRANCISCO (Reuters) - Shares of Yahoo Inc. surged on Friday [Nov. 28], after billionaire activist investor Carl Icahn disclosed that he has increased his stake in the Internet company.

According to a filing with the Securities and Exchange Commission, Mr. Icahn bought roughly 6.8 million Yahoo shares over three days this week, paying around $67 million. Mr. Icahn, who sits on Yahoo's board, now owns 75.6 million of the company's shares, or a 5.4% stake valued at around $870 million based on Yahoo's closing share price on Friday.

Earlier this year, Mr. Icahn threatened to launch a proxy fight against Yahoo and oust Chief Executive Jerry Yang in an effort to push the company to accept Microsoft Corp.'s $47.5 billion acquisition offer. He later struck a deal with Yahoo and joined its board last summer. Mr. Icahn began amassing Yahoo shares during the company's merger talks with Microsoft.

Earlier this month, Mr. Yang said he was stepping down as CEO. The company is searching for his replacement.

Shares of Sunnyvale, Calif.-based Yahoo rose 93 cents, or 8.8%, to close the abbreviated trading session at $11.51 per share.

By Gabriel Madway