A former securities analyst extradited to the U.S. from Hong Kong in March pleaded guilty to his role in an insider trading scheme involving IBM’s (NYSE: IBM) $1.2 billion acquisition of SPSS Inc.

Trent Martin, 34, an Australian citizen, entered his plea to a single count of conspiracy in a hearing yesterday before U.S. District Judge Andrew L. Carter Jr. in Manhattan. Martin told Carter that he made about $7,600 from trading on the tip, which he received from an unidentified attorney working on the deal.

“I knew my actions were wrong and in violation of the law and I apologize to the court for my conduct,” Martin said.

Martin, who faces as long as five years in prison when he’s sentenced March 14, is cooperating with the government in hopes of leniency. Carter agreed to a request by lawyers for both sides that he be allowed to return to Sydney until he’s sentenced. Martin will probably face deportation to Australia as a result of the guilty plea, Carter said.

Martin said he received the tip from the lawyer, a close friend, in June 2009. He shared the information with his Manhattan roommate, Thomas Conradt, who was a stockbroker. Conradt passed the information to his co-worker and friend David Weishaus, who in turn tipped two other brokers.

Securities Fraud

Conradt pleaded guilty in April to one count of conspiracy and two counts of securities fraud. Weishaus has pleaded not guilty.

Martin worked at Royal Bank of Scotland Group Plc in the U.S. and an RBS joint venture in Australia before joining Nomura Holdings Inc. in September 2011, according to two people familiar with the situation who asked not to be identified because they aren’t authorized to speak about the matter.

The Financial Industry Regulatory Authority lists a Trent Martin who left ABN Amro Bank NV in 2009 to work at the Stamford office of RBS, which participated in ABN Amro’s takeover in 2007. Martin’s broker registration at RBS ended in November 2010, Finra documents show.

The case is U.S. v. Martin, 12-cr-00887, U.S. District Court, Southern District of New York (Manhattan).