A spokeswoman for Bear Stearns & Co., which has a majority stake in Bear Wagner, also confirmed that the specialist firm could be penalized by the NYSE itself.

On Friday, specialist firms LaBranche & Co., Fleet Specialist and Van Der Moolen all announced they had received "Wells notices" from the SEC, warning them of impending civil action, as well as notice from the NYSE about potential penalties.

A fifth firm, Goldman Sachs subsidiary Spears, Leeds & Kellogg, received notice of SEC and NYSE enforcement actions as well, sources close to the matter told The Associated Press last week.

The five firms, which manage buy-sell auctions on the floor of the NYSE, are accused of illegally managing prices during transactions in order to skim profits for their firms.