A senior Nasdaq Stock Market official told customers yesterday afternoon that it would have pulled the plug on Facebook's initial public offering had it known the full extent of the technical problems that plagued its systems.

On a conference call with brokers after yesterday's close, Eric Noll, Nasdaq OMX's head of transaction services, said the exchange "by no means would have gone forward" with the much watched Facebook debut if it had known problems would disrupt a "normal trading day".