According to reports from Bloomberg, Ackman was positive on the company's repurchase plan which he said was "aggressive." He was also positive on the new CEO George Jones, a former Saks executive.
Ackman recently told Barron's that he increased his stake in Borders' rival Barnes & Noble (NYSE:BKS) from 2.3% to 8%. Ackman made similar comments on Barnes & Noble, saying the stock is significantly undervalued.
Ackman may be best known for his fight to implement changes at McDonald's Corp. (NYSE:MCD). He was also instrumental in getting Wendy's International (NASDAQ:WEN) to make aggressive changes, including spinning off its Tim Horton's (NYSE:THI) chain.
Shares of Borders Group are up about 10% to $23.71 in early action Thursday.
Related: Media coverage: Bloomberg • TheStreet.com • Commentary: Excerpt from the mentioned Barron's feature • Borders Wobbles: Could It Be Ripe for a Takeover Bid? • Borders Needs a Savior