U.S. authorities are conducting a criminal probe into Bank of America Corp's purchase of Merrill Lynch, the Charlotte Observer reported on Friday.

The investigation is being conducted by the U.S. Department of Justice and Federal Bureau of Investigation and has been underway for six months, the newspaper said.

The scope and potential outcome of the probe are unknown, it said.

Scott Silvestri, a Bank of America spokesman, told Reuters the bank has provided thousands of documents to various government entities and there was no basis for charges against the company or individuals on the management team.

In recent filings with the Securities and Exchange Commission, the bank disclosed that it was cooperating with various investigations from governmental authorities but gave no specifics.

A spokeswoman for the Justice Department declined to comment. The FBI did not immediately return calls seeking comment.

A federal criminal probe would be a new wrinkle in a year-long wave of legal problems for the largest U.S. bank. Bank of America, based in Charlotte, North Carolina, has been subject to a wave of civil litigation since it purchased Merrill Lynch on January 1.

The SEC and the attorneys general of New York and North Carolina are investigating whether Bank of America failed to disclose to shareholders Merrill Lynch's operating losses and bonus payments before the merger was approved.

Bank of America shares were off 2 cents at $17.59 in morning trading on the New York Stock Exchange.

(Reporting by Joe Rauch; additional reporting by Elinor Comlay; editing by John Wallace)