Activist investor Third Point Capital has drawn blood in its war to knock out the management of Yahoo (Nasdaq: YHOO), the No. 3 search engine: CEO Scott Thompson has apologized for lying.

In the second note to employees of the Sunnyvale, Calif., search and media company in two business days, Thompson admitted he falsified academic credentials on his resume, repeated in official filings with the U.S. Securities and Exchange Commission.

For that I take full responsibility and I want to apologize to you, Thompson wrote Yahoo's 14,100 employees.

In the proxy filings cited by Third Point, a New York hedge fund that owns 5.8 percent of Yahoo's shares, the company said the new CEO held degrees in accounting as well as computer science from Stonehill College.

Thompson, 54, only has an accounting degree. Third Point also charged Yahoo director Patti Hart, 56, who chaired the search that recruited the new CEO, inflated her credentials to say she held degrees in marketing and economic from Illinois State University whereas her degree is in business administration.

Thompson said the board of directors would conduct a full probe and asked for staff spport.

Yahoo shares rose a penny to $15.33 on Tuesday.