The Delaware Court of Chancery has dismissed a shareholder challenge to the $400 million purchase of network solutions company Cyan Inc. and denied the investors' quasi-appraisal bid to recover damages for alleged disclosure deficiencies in the run-up to the merger.

A class of Cyan investors in 2015 accused Cyan's board of breaching its fiduciary duties and withholding information that prevented shareholders from deciding whether to vote their shares against the deal—which sold the company to Ciena Corp.—and instead pursue their statutory appraisal rights.

The directors, they said in a three-times amended complaint, had acted out of self interest in approving the deal in order to bolster their indemnification rights in the face of a pending securities action in California.