Talecris Biotherapeutics is being sued by an investment fund over its proposed $4 billion buyout by Grifols SA of Spain.
The Laborers Local 235 Benefit Funds filed the suit Monday in Wilmington, Del., Chancery Court, Bloomberg News reported.
The suit contends that Talecris officials "are well aware of the company's intrinsic value and the fact that Talecris shares are significantly undervalued."
Company officials have a duty to get the best price for shareholders, the suit charges.
Such lawsuits aren't unusual when a publicly traded company agrees to a takeover. The suit isn't likely to derail the deal, since the private equity firms that own about half of Talecris' shares have agreed to the terms.
Grifols agreed to pay Talecris shareholders $19 in cash, plus 0.641 of its shares for each Talecris share. That values Talecris shares at nearly $26 each.
Talecris shares began trading publicly last fall at $19 each, but had fallen in recent months. On the last trading day before the Grifols deal was announced, the shares closed at $15.92.
The shares closed Monday at $21.88, up 7 cents.
Talecris, which is based in Research Triangle Park, makes medicines from blood plasma at its massive facility in Clayton. It employs about 2,200 people in the Triangle. Many of those employees received shares in the initial public offering.