A former Long Island investment adviser pleaded guilty Tuesday to a single count of conspiracy to commit securities fraud Tuesday, the Eastern District U.S. Attorney’s Office said.

Tibor Klein was accused of using information obtained from his client and friend, former Arent Fox partner Robert Schulman, about the $3.6 billion merger of Pfizer Inc. and King Pharmaceuticals. Klein reportedly earned nearly $9,000 personally off the merger while netting more than $319,000 for his clients.