SAN FRANCISCO (Reuters) - A CVS Caremark Corp subsidiary agreed to pay $77.6 million to settle an investigation that it unlawfully sold a key ingredient to manufacture methamphetamine, the U.S. Attorney in Los Angeles said on Thursday.

CVS Pharmacy Inc admitted it sold pseudoephedrine to criminals who used it to make the drug, according to the U.S. Attorney's office. CVS eventually changed its practices to prevent the sales after it became aware of the investigation, the government said in its statement.

(Reporting by Dan Levine, editing by Gerald E. McCormick)