"It appears as though material information was not disclosed," said Robert Weiser, one of the plaintiff lawyers in the class action suit. "We believe that the offering was conducted unfairly and it harmed public stockholders."
The suit was filed in the U.S. District Court for the Southern District of New York in Manhattan.
According to a report published by Reuters, Morgan Stanley (MS, Fortune 500) shared a negative assessment of the social network with major clients ahead of Facebook's (FB) IPO, which debuted last week.
"We believe the lawsuit is without merit and will defend ourselves vigorously," said a Facebook spokesperson.
Morgan Stanley declined to comment.
Other underwriters targeted by the lawsuit include Barclays Capital, Goldman Sachs (GS, Fortune 500), JPMorgan Chase (JPM, Fortune 500) and Merrill Lynch, a unit of Bank of America (BAC, Fortune 500).
Weiser and his colleagues are representing Facebook investors Brian Roffe, Jacob Salzmann and Dennis Palkon.
Weiser said that more plaintiffs may join the class action lawsuit. He said that monetary damages have yet to be specified.
Facebook's stock price finally rose Wednesday for the first time since its Nasdaq launch on Friday.
