According to newspaper reports, more than 100 clients were sent the message by an analyst at the bank.
Papers filed by GM with the Securities and Exchange Commission (SEC) revealed the details of the alleged leak.
Investors may be able to seek either a refund or damages if the email is considered to have broken laws surrounding IPOs put in place by the SEC.
In the filing, which was quoted by City AM, GM said: âWe had no knowledge of the email until after it was sent, and the email does not reflect our views.â
GM is looking to raise up to $10 billion from the IPO as part of a bid to repay $50 billion worth of fiscal stimulus provided to the firm by the government during the financial crisis.
The IPO, which is being launched on November 18th, is expected to see the governmentâs share in GM reduced to approximately 40 per cent.
By Jim Ottewill