Wal-Mart was hit with $110 million in US federal and state fines Tuesday after pleading guilty to criminal charges of mishandling hazardous waste and pesticides at its retail stores.

The world's largest retailer was fined for dumping hazardous chemicals in city trash bins and sewer systems in cases filed by the Los Angeles and San Francisco municipalities.

In addition, the US Justice Department said Wal-Mart Stores had mishandled pesticides it had sent as damaged products to a Missouri recycling facility that resulted in them being mixed together and put on sale again in a process that violated federal laws regulating pesticide processing.

Wal-Mart pleaded guilty to six misdemeanor counts of violating the Clean Water Act in the California cases, and, in the Missouri case, one charge of violating the Federal Insecticide, Fungicide and Rodenticide Act.

Prosecutors in San Francisco said that through January 2006, the company did not have any program or training in place to show employees how to properly handle hazardous waste.

"By improperly handling hazardous waste, pesticides and other materials in violation of federal laws, Wal-Mart put the public and the environment at risk," said Ignacia Moreno, assistant attorney general for the Environment and Natural Resources Division, in a statement.

"Truckloads of hazardous products, including more than two million pounds of pesticides, were improperly handled under Wal-Mart's contract," said Tammy Dickinson, US attorney for the Western District of Missouri.

"Today's criminal fine should send a message to companies of all sizes that they will be held accountable to follow federal environmental laws."