The New York Stock Exchange delayed the opening of three stocks today due to erroneous orders sent to the exchange by a brokerage firm.

The delayed opening affected Jefferies Group, Inc., AT&T and Wyeth. The exchange pointed to a series of erroneous orders from a brokerage firm as the reason for the delay. ”Floor professionals recognized the problem before trading began, thus avoiding public trading at incorrect prices on the NYSE,” it noted.

“We are actively working through the process of canceling these orders. Jefferies has now been opened for trading and we will open the other two stocks as soon as possible,” it said.