The onetime managing clerk at New York’s Simpson Thacher & Bartlett, the lone remaining defendant in a New Jersey-based criminal case, has admitted to his role in a lucrative insider-trading scheme.

Steven Metro pleaded guilty Nov. 12 to utilizing sensitive information from the firm’s mergers and acquisitions practice to tip off a friend on stock purchases that netted them, as well as the broker, upward of $5.6 million.