The Delaware Supreme Court has rejected an appeal by billionaire Ron Burkle in a lawsuit challenging a poison pill plan adopted by Barnes & Noble Inc. after he doubled his stake in the company.

After hearing arguments Wednesday, the court on Thursday affirmed a judge's ruling last year upholding the poison pill plan, which limited a shareholder's stake in the company to 20 percent.

Burkle argued that New York-based Barnes & Noble had created an unfair playing field favoring the family of chairman and founder Leonard Riggio, which owns more than 30 percent of its common stock.

Burkle waged an unsuccessful proxy fight after the ruling but said he would continue to press for changes at the nation's largest brick-and-mortar book seller.