Aletheia Research and Management disclosed in a filing with the Securities & Exchange Commission Wednesday morning that it had cut its stake in Barnes & Noble to 5.2 million shares, or 8.65% of the company from the 10.59% stake it held in April. Aletheia is B&N’s third largest shareholder after chairman Len Riggio and outside investor Ron Burkle.

While Aletheia had been selling and buying some B&N’s shares prior to the $17 per share bid by John Malone, the firm significantly increased its selling effort after the May 19 bid. Just prior to Malone’s offer Aletheia sold 13,025 shares for $13.97 per share; the next day it sold 15,080 shares for $18.33 per share. In the first three days of June Aletheia sold the greatest amount of shares, totaling approximately $10.4 million at prices ranging from $18.60 to $18.90 per share.

For the remaining 5,211,645 shares it still holds, Aletheia reported that it paid $98.3 million, putting the price at about $18.86 per share. B&N’s shares closed at $18.97 per share Tuesday and were up in early trading Wednesday. Aletheia’s willingness to sell large chunks of its holdings could indicate it does not believe bids for B&N will come in much higher than Malone’s $17 per share offer.