(Reuters) - The FBI is in the process of arresting Anthony Chiasson, who co-founded the Level Global Investors hedge fund, and others as part of the government's sweeping probe into insider trading, a person familiar with the matter said on Wednesday.

Level Global is one of several firms that were raided by the FBI in late 2010 in the probe. The source declined to be named because of a lack of authority to speak about the expected arrests.

A lawyer for Chiasson did not immediately return a request for comment.

More than 50 people have been arrested or charged in overlapping probes that were first unveiled in October 2009. Most of these people have pleaded guilty or been convicted.

(Reporting by Matthew Goldstein, Basil Katz and Jonathan Stempel in New York and Svea Herbst-Bayliss in Boston; editing by John Wallace)