The Delaware Court of Chancery on Thursday dismissed a shareholder class action that accused the directors of a paper and packaging company of improperly approving a merger-of-equals that allegedly left $3 billion on the negotiating table.

Shareholders of MeadWestvaco Corp. had sued in 2015 over the company's $9 billion tie-up with Georgia-based RockTenn Co., arguing that MeadWestvaco board members had forced the deal in an effort to stave off a potential attack by activist investor Starboard Value, which had threatened shakeups at the company.

The deal, which closed in July 2015, yielded a 9.1 percent premium to MeadWestvaco shareholders and created a new firm, known as WestRock.