(Reuters) - Canada's TD Bank is expected to pay about $3 billion in penalties as part of a settlement with U.S. regulators and prosecutors over charges it failed to properly monitor money laundering by drug cartels, the Wall Street Journal reported.

The bank's U.S. unit is expected to plead guilty on Thursday to the charges, the report said on Wednesday.

TD Bank did not immediately respond to a Reuters' request for comment.

As part of the agreement, the bank's primary U.S. regulator, the Office of the Comptroller of the Currency (OCC), is also expected to impose an asset limit barring the Canadian lender from growing above a certain level in the country, the newspaper reported, citing people familiar with the matter.

Both the U.S. Department of Justice (DOJ) and the Treasury Department's Financial Crimes Enforcement Network (FinCEN) are planning to put independent monitors in place to watch the lender closely and ensure compliance with the pacts, the report said.

The FinCEN monitor is expected to be in place for four years, the WSJ reported, citing one person familiar with the matter.

The settlement will include the DOJ, the FinCEN, OCC and the Federal Reserve among which the Justice Department will take the biggest slice of the penalties amounting to about $1.8 billion with the FinCEN getting $1.3 billion, the report said.

Spokespeople for the DOJ, the OCC and the FinCEN did not respond immediately to Reuters' requests for comment.

(Reporting by Pretish M J in Bengaluru; Editing by Subhranshu Sahu)