Pershing Square Capital Management raised its stake in Family Dollar Stores Inc. to 8.9 percent, according to a regulatory filing made on Thursday, just weeks after its influential leader, Bill Ackman, praised the retailer as an attractive LBO candidate.

Shares of Family Dollar, which caters to low-income shoppers with a variety of household goods and food, climbed 3.5 percent to $53.29, outpacing a broad market increase. The shares rose just 3.6 percent since the beginning of the year through Wednesday.

Pershing Square now holds 10.87 million shares, or 8.9 percent of the company's stock, according to the filing with the U.S. Securities and Exchange Commission. The firm held close to 5.8 million shares, or 4.7 percent of Family Dollar's shares, as of March 31, according to Thomson Reuters data.

Two weeks ago at the Ira Sohn Investment Conference, Ackman said that Family Dollar could become an attractive leveraged buyout candidate. Other hedge funds have also bought the stock this year.