The preliminary ruling by the Delaware Court of Chancery, a premiere venue for shareholder lawsuits, found Merrill Lynch could have aided the Zale board breach their duties to investors. Zale agreed in 2014 to be acquired by rival Signet Jewelers for $21 per share, or $690 million. TIG Advisors, which held nearly 10 percent of Zale stock, called the deal grossly unfair and shareholders only narrowly approved the sale.