Aletheia Research and Management, which at one point owned 15.1% of Barnes & Noble stock, has reduced its stake to 12.7%, the firm said in a filing made with the Securities & Exchange Commission Wednesday. Aletheia now owns 7.67 million shares worth approximately $108 million; it said it had paid $149.8 million for the shares.

Aletheia had provided support for the alternate slate of candidates nominated by Ron Burkle that challenged B&N chairman Len Riggio and two other board backed candidates for a seat on the board of directors. During the campaign, B&N charged that Aletheia was working with Burkle to take over B&N without paying a premium price. The Riggio slate eventually prevailed in the proxy contest. Despite the sale of stock, Aletheia remains B&N’s third largest shareholder, after Riggio and Burkle.

The B&N committee established to review the company's strategic options, including the possible sale of the retailer, is expected to make its recommendation in the first quarter of 2011. The fact that Aletheia decided to sell some shares before a possible sale suggests the firm doesn't think a significant offer is in the works.