The Financial Industry Regulatory Authority says it fined investment banks Barclays, Goldman Sachs and Merrill Lynch $1 million each for providing incomplete and inaccurate information about trades the companies conducted.

Finra says that the trading information is required to be submitted upon request but it says data was missing, had incorrect customer names and contact information or inaccurate details about the transactions.

Regulators use the trading data, known as "blue sheets," to investigate potential insider trading or other manipulations of the market.

The regulator says Barclays PLC, The Goldman Sachs Group Inc. and Merrill Lynch neither admitted nor denied the charges by settling the cases.

Finra also issued a complaint against Wedbush Securities for the same reasons, but says that case hasn't been decided yet.