By Nate Raymond

NEW YORK (Reuters) - A former investment adviser at an Oppenheimer Holdings Inc unit pleaded guilty on Tuesday to charges that he engaged in an insider trading scheme based on information supplied by a childhood friend working at Pfizer Inc.

David Hobson, 48, entered his plea in Manhattan federal court to conspiracy and securities fraud charges over conduct that began while he was at Royal Bank of Canada unit RBC Capital Markets and then continued at Oppenheimer & Co Inc.

Hobson, a Providence, Rhode Island, resident, admitted that he executed trades based on inside information supplied by Michael Maciocio, a friend at Pfizer who pleaded guilty in May as part of a deal to cooperate with prosecutors.

"I'm sorry for these actions, and I apologize to the court and to my family," Hobson said in court.

Under a plea agreement, Hobson agreed to forfeit almost $386,000 and not appeal any prison sentence of 2-1/2 years or less. U.S. District Judge Laura Taylor Swain scheduled his sentencing for March 2.

The case was announced in June amid a resurgence of insider trading cases this year in Manhattan, where prosecutors have wrestled with a 2014 appellate ruling that limited the scope of insider trading laws.

According to prosecutors, Hobson and Maciocio engaged in an insider trading scheme from 2008 to 2014 based on information obtained by Maciocio, a director of chemical research and development at Pfizer.

As part of that job, Maciocio at times evaluated Pfizer's capacity to manufacture drugs that other companies Pfizer considered potential acquisition targets or partners were developing, authorities said.

While Maciocio was not typically given the identity of a company in a potential deal, with Hobson's help he performed research to discern its identity, the indictment said.

After identifying the company, Maciocio then passed the information to Hobson, his stockbroker, who executed trades in accounts belonging to himself, Maciocio, and clients of Oppenheimer and RBC, prosecutors said.

Trades by Hobson in the stocks of Medivation Inc, Ardea Biosciences Inc and Furiex Pharmaceuticals Inc resulted in profits of $180,000 for himself, $40,000 for Maciocio and $150,000 for certain of Hobson's clients, prosecutors said.

The case is U.S. v. Hobson, U.S. District Court, Southern District of New York, No. 16-cr-351.

(Reporting by Nate Raymond in New York; editing by Andrew Hay and Grant McCool)