Nasdaq said in a statement that it experienced 'several problems' with its trade reporting interface to the Securities Industry Automation Corp. (SIAC) Wednesday afternoon and evening.

SIAC is an electronic system that disseminates market data and runs computer trading systems. It is two-thirds owned by the New York Stock Exchange (NYSE) and one-third owned by the American Stock Exchange.

As a result of the problem, Nasdaq said the companies had incorrect consolidated closing price data for NYSE and American Stock Exchange-listed stocks for that day, Nasdaq said in a statement. 'At 3:39 p.m., EST, on Wed., Jan. 18, Nasdaq experienced a technical issue with its trade reporting interface to the Securities Industry Automation Corporation. Due to the problem, SIAC rejected approximately 81,000 Nasdaq trade transactions in New York Stock Exchange- (NYSE), American Stock Exchange, and Archipelago Exchange listed issues reported after 3:39 p.m.'

Later in that same day, at 5:50 p.m., EST, Nasdaq had a second problem with its SIAC interface. Nasdaq said it resubmitted 16,669 trade transactions from the morning hours, but because most of those transactions were sent with a 'regular sale condition modifier,' SIAC calculated bad consolidated last sale data for about 1,500 securities.

Nasdaq officials declined to offer any additional details about what happened.