The FTC is probing some recent stock buys.

The Federal Trade Commission said the purchases by investment banking firms may have violated antitrust regulations. If so, their clients could be subject to substantial penalties, said Jeffrey L. Zuckerman, director of the FTC Bureau of Competition. Investigators have uncovered several instances in which clients arranged for investment bankers to buy voting securities of a company on their behalf but did not report the purchases to federal agencies as required. No specifics were given. In the cases under investigation, the bankers bought the stock after their clients promised either to buy it from them at a stated price or to reimburse them if the stock was sold at a loss.