CONCORD, N.H. — A former New Hampshire investment banker has pleaded guilty in federal court to defrauding a client of about $2 million.

Court records say 44-year-old Karl Edward Hahn, formerly of New Castle, invited a client to join him in what he referred to as an “off the books investment” in 2009.

He said he and the client would each contribute $2 million, which Hahn would then loan to three people who would repay the money within 90 days with interest, substantially above market rates.

Hahn said he used the client’s money to pay personal expenses.

In 2011, the New Hampshire Bureau of Securities Regulation barred Hahn from being licensed to sell securities. He’s scheduled for sentencing Nov. 8. The terms of the plea require him to serve 18 months in prison.