Mandiant Inc. was sued in New York by a shareholder alleging the cybersecurity company made incomplete and misleading disclosures while asking investors to approve its proposed $5.4 billion purchase by Alphabet Inc.’s Google.

The deal, announced on March 8, was the second-biggest ever for Google, adding internet security products that will aid its cloud-computer division as the company competes with larger rivals Amazon Web Services and Microsoft Corp.

In a lawsuit filed Friday in federal court in Manhattan, shareholder Shiva Stein said a proxy statement filed by Mandiant with the U.S. Securities and Exchange Commission and sent to investors recommending a vote in favor of the deal contains “materially incomplete and misleading” information from Mandiant’s financial adviser, Goldman Sachs Group Inc.

The statement fails to give information about financial projections that were provided to Goldman by Mandiant’s management and provides values for financial metrics not included in generally accepted accounting principles without reconciling them to comparable measures, according to the complaint. 

The suit seeks to block the deal or force Mandiant to disclose the omitted information.

Mandiant didn’t immediately respond to a request for comment.

The transaction signals that Alphabet has returned to large deal making despite intense regulatory scrutiny. Buying Mandiant will give Google a wider range of software tools to protect clients as it seeks to expand its third-place cloud-infrastructure unit, which sells computing power and storage via the internet.

The case is Stein v Mandiant, 22-cv-2697, U.S. District Court, Southern District of New York.