The US securities industry regulator has fined the investment banking arm of Credit Suisse $170,000 (€137,000) and ordered the bank to pay restitution of $600,000 in connection with the flotation of MP3.com, the US internet music service.

The National Association of Securities Dealers (NASD) found that Credit Suisse First Boston (CSFB) failed to provide six customers with the best available price at the opening of the first day of trading and that the bank failed to honour its published quotations for the stock in 30 instances that day.