A former Morgan Stanley compliance officer and her husband are scheduled to plead guilty for their roles in an insider-trading case that prosecutors said was part of the largest such scheme on Wall Street since the 1980s.

U.S. prosecutors in March said Randi Collotta, 30, a lawyer and Morgan Stanley compliance officer, tipped off her husband, Christopher Collotta, 34, and Florida broker Marc Jurman about pending deals. These included Penn National Gaming Inc.’s $2.1 billion acquisition of Argosy Gaming Co. and Adobe Systems Inc.’s $3.4 billion purchase of Macromedia Inc., both in 2005.

“The government anticipates that both defendants will be ready to enter guilty pleas on May 10, 2007,” Assistant U.S. Attorney Andrew Fish said in a letter to a Manhattan federal judge that was posted by the court on the case docket.

The charges were part of an insider-trading crackdown by U.S. prosecutors against employees at New York-based Morgan Stanley, the world’s second-biggest securities firm by market value, UBS AG and Bear Stearns. In all, 13 people were charged in separate schemes that authorities said stretched over five years and yielded more than $15 million in illegal profits.

“Randi Collotta is prepared to address the charges in court,” her lawyer, Kenneth Breen of Paul, Hastings, Janofsky & Walker, said, declining to comment further.

Christopher Collotta’s lawyer, Brian Rafferty, of Dornbush Schaeffer Strongin & Venaglia, declined to comment. Mark Lake, a spokesman for Morgan Stanley, declined to comment.

When charged, prosecutors said Collotta, who left Morgan Stanley in June 2005, faced more than 10 years in prison. She’ll receive substantially less under federal sentencing guidelines.