In the latest twist in the government's multi-year prosecution of the Enron Corp. scandal, the Justice Department moved Wednesday to drop charges against a former Merrill Lynch & Co. official days before a scheduled retrial involving the only criminal case brought against Wall Street figures in the alleged misdeeds at the onetime energy giant Enron Corp. .

The Justice Department asked a federal judge in Houston to drop fraud and conspiracy charges against James A. Brown, a former Merrill official who along with three former...