The Securities and Exchange Commission slapped Monsanto with an $80 million civil penalty for violating accounting rules and misstating past earnings related to rebates on its flagship weedkiller Roundup. Two accounting executives and a retired sales executive also agreed to pay penalties to settle the charges.

And while the SEC found no personal misconduct by Monsanto CEO Hugh Grant, the biotech seed giant disclosed Tuesday that Grant already had reimbursed the company $3.2 million in pay due to the restatement of corporate earnings in fiscal years 2009 through 2011.

The penalty is another black eye for the Creve Coeur-based company, which has had a number of high-profile setbacks in the past year.