The FBI has arrested two high profile financial brokers suspected of insider trading, much of it in IT shares, as part of a vast probe.

Todd Newman, a senior manager with the Diamondback Capital Management hedge fund, and Anthony Chiasson, a co-founder at Level Global investors, were arrested this morning in Boston and New York respectively.

Newman oversaw IT stock investments at Diamondback. Chiasson's Level firm principally trades in IT and finance shares.

Meanwhile, the FBI also arrested Jon Horvath, an employee at hedge fund Sigma Capital Management, which trades in stocks from a range of different sectors. A fourth person is being sought.

The companies have not publicly commented.

Details remain scarce, but the FBI is expected to announce the charges later today. It remains unclear which companies' stocks were involved.

The news follows the conviction of Galleon co-founder Raj Rajaratnam, who was accused of illegally trading shares in AMD, IBM, Intel and 3Com, based on insider information. He received an 11 year jail sentence.