June 16 (Reuters) - A Boston-area amateur golfer was convicted on Tuesday of engaging in insider trading by tipping off friends about the business activities of American Superconductor Corp.

Despite hearing the information in confidence, McPhail beginning in 2009 began sharing with his friends inside information about the company's business activities and earnings announcements, prosecutors said.

Over a two-year period, McPhail's friends made over $500,000 illegally trading on the tips, prosecutors said. Parigian alone made more than $267,000, prosecutors have said.

The trial came after U.S. District Judge Denise Casper rejected a bid to dismiss the case in light of a December ruling by the 2nd U.S. Circuit Court of Appeals in New York that curtailed authorities' ability to pursue insider trading.

While the decision, which reversed the convictions of hedge fund managers Todd Newman and Anthony Chiasson, only applied to judges in New York, Vermont and Connecticut, McPhail, Parigian and defendants in other states began citing it in their cases.

(Reporting by Nate Raymond in New York; Editing by Diane Craft)