Microsoft Corp. co-founder Paul G. Allen has sold about 1.2 million DreamWorks Animation SKG Inc. shares, or nearly a third of his remaining stake in the film studio, according to a regulatory filing Friday.

In a Form 4 filed with the Securities and Exchange Commission, Allen reported selling the Class A shares on Wednesday and Thursday for $30.22 to $30.34 apiece, or a total of about $35.3 million.

The shares were held by DW Investment II Inc., which is owned by Allen.

Allen now owns about 3.1 million Class A shares, or a 4 percent stake based on 79.6 million Class A shares outstanding as of March 31.

Last August, Allen resigned from the company's board and sold 10.2 million shares in a public offering. DreamWorks also repurchased 4.8 million shares of Allen's stock.

Allen invested more than $500 million in DreamWorks when it launched in 1995 as a combination live-action and animation studio.

DreamWorks went public in 2004 in large part to begin repaying Allen's investment.

Insiders file Form 4s with the SEC to report transactions in their companies' shares. Open market purchases and sales must be reported within two business days of the transaction.