A law firm clerk at Simpson Thacher & Bartlett LLP and a stockbroker were charged in what U.S. authorities said was an insider-trading scheme that netted more than $5.6 million in illicit profit.

Steven Metro, 40, the managing clerk at Simpson Thacher in New York, was accused of stealing confidential information on mergers, acquisitions, and tender offers and tipping a middleman who passed it to Vladimir Eydelman, 42. Eydelman, a broker, worked at Oppenheimer & Co. and later Morgan Stanley, federal authorities said. The middleman became a cooperating witness.

The men invested more than $33 million over four years to buy securities in 13 transactions, including OfficeMax Inc. and Sirius XM Holdings Inc., authorities said. Eydelman bought securities for himself, family members, friends, and clients, including the cooperating witness, they said. Metro and Eydelman were arrested today and are scheduled to appear in federal court in Newark, New Jersey.