The FBI arrested a Credit Suisse investment banker on Thursday and charged him with securities fraud for allegedly tipping an accomplice in Pakistan to nine transactions the bank was working on, including a leveraged buy-out of TXU and Babcock & Brown’s acquisition of Northwestern Energy.

Hafiz Nazeem, 37, began work as a junior banker on Credit Suisse’s global energy team in March 2006 and soon began phoning tips to a banker in Pakistan. The accomplice allegedly placed dozens of trades ahead of merger announcements and netted more than $7m, according to the US Attorney’s office in Manhattan, which will prosecute the case.