The market for derivatives grew at the fastest pace in at least nine years to $516 trillion in the first half of 2007, the Bank for International Settlements said. Credit-default swaps, contracts designed to protect investors against default and used to speculate on credit quality, led the increase, expanding 49 percent to cover a notional $43 trillion of debt in the six months ended June 30, the BIS said in a report published late yesterday. Derivatives of debt, currencies, commodities, stocks and interest rates rose 25 percent from the previous six months, the biggest jump since the Basel, Switzerland-based bank began compiling the data. Investors have been turning to credit derivatives as a way to speculate on a growing risk of defaults amid record U.S. mortgage foreclosures. The money at risk through credit-default swaps increased 145 percent from last year to $721 billion, the report said. The amount at stake in the entire derivatives market is $11.1 trillion, according to the BIS, which was formed in 1930 to monitor financial markets and regulate banks. Derivatives are financial instruments derived from stocks, bonds, loans, currencies and commodities, or linked to specific events like changes in interest rates or the weather. The report is based on contracts traded outside of exchanges in over-the- counter market.