NEW YORK (Reuters) - A former Oppenheimer & Co Inc investment adviser was arrested on Friday on charges he traded on inside information supplied by a childhood friend working at Pfizer Inc (>> Pfizer Inc.) about deals that drugmaker was considering.

David Hobson, who during the alleged scheme also worked for RBC Capital Markets, was charged in an indictment filed in Manhattan federal court for making illegal trades that earned him over $187,000 (£128,858) and about $145,000 for his customers.

His friend, Michael Maciocio, secretly pleaded guilty on May 20 to charges related to the scheme, which ran from 2008 to 2014 and which the U.S. Securities and Exchange Commission in a lawsuit said earned him $116,000 from his own insider trading.

Hobson, 47, was arrested at his home in Providence, Rhode Island on charges of conspiracy and securities fraud. He was released later in the day following a court hearing. His lawyer declined comment.

Maciocio, 46, has agreed to cooperate with prosecutors pursuing the case, according to his plea agreement. His lawyer did not respond to requests for comment.

The charges were brought by Manhattan U.S. Attorney Preet Bharara, who since 2009 has overseen an insider trading crackdown that has resulted in charges against 104 and the conviction of 79.

According to authorities, Maciocio in his role at Pfizer as director of chemical research and development, received information about potential deals relevant to his tasks evaluating manufacturing demands and capacity.

While Maciocio was not typically given the identity of the company in a potential deal, he used the information to perform research to discern its identity, sometimes with Hobson's help, authorities said.

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

The tips enabled Hobson to illegally trade in the stocks of Medivation Inc (>> Medivation Inc), Ardea Biosciences Inc and Furiex Pharmaceuticals Inc, the indictment said.

The former employers of Hobson and Maciocio were not named in the court papers, but Pfizer, Oppenheimer, a unit of Oppenheimer Holdings Inc (>> Oppenheimer Holdings Inc. (USA)), and RBC, a unit of Royal Bank of Canada (>> Royal Bank of Canada), confirmed their employment.

Oppenheimer said it has "cooperated extensively" with authorities. Pfizer said it "takes these allegations seriously and is cooperating fully with the authorities."

The cases in the U.S. District Court, Southern District of New York, are U.S. v. Hobson, No. 16-cr-351, and Securities and Exchange Commission v. Maciocio, No. 16-cv-4139.

(Editing by Steve Orlofsky and Alistair Bell)

By Nate Raymond