The brother of an imprisoned insider trading ringleader was acquitted by a federal jury in lower Manhattan yesterday on a single count of conspiring to commit insider trading.

In a rare acquittal in the Southern District, Rengan Rajaratnam, the founder of Sedna Capital Management and the younger brother of convicted Galleon Hedge Fund group founder Raj Rajaratnam, was cleared of charges that he traded on nonpublic confidential information on Advanced Micro Devices, Inc. (AMD).

Rengan Rajaratnam, represented by Daniel Gitner and Michael Longyear of Lankler Siffert & Wohl, is the only person acquitted during U.S. Attorney Preet Bharara’s five-year campaign against insider trading.

Eighty-one people and four corporations have either been convicted or pleaded guilty in the probe, which was highlighted by the 2011 trial of Raj Rajaratnam, currently serving an 11-year prison sentence.

Before Judge Naomi Reice Buchwald (See Profile), the government attempted to prove that Raj Rajaratnam told Rengan, 42, about a pending deal with AMD and the government of Abu Dhabi in 2008.

Buchwald had already dealt a blow to the government’s case when she dismissed two counts of securities fraud, leaving only the single conspiracy count for the jury to consider. The panel deliberated less than four hours before delivering a verdict.

The government was represented by Assistant U.S. Attorneys Christopher Frey and Randall Jackson.