New York, May 9, 2007—Today the American Stock Exchange® (Amex®) launched trading in options on the following Amex-listed exchange traded funds:

• United States Natural Gas Fund (UNG)
• United States Oil Fund, L.P. (USO)

United States Natural Gas Fund (UNG) options will open with strike prices of 40-65 (1 pt increments) and position limits of 2,500,000 shares. The options will trade on the January expiration cycle. The specialist will be AGS/STR/OTA. The investment objective of UNG is to have the changes in percentage terms of the unit’s net asset value (NAV) reflect the changes in percentage terms of the price of natural gas delivered at the Henry Hub, Louisiana, as measured by the changes in the price of the futures contract on natural gas traded on the New York Mercantile Exchange (the “Benchmark Futures Contract”) that is the near month contract to expire, except when the near-month contract is within two weeks of expiration, in which case it will be measured by the futures contract that is the next month contract to expire, less UNG’s expenses. It is not the intent of UNG to be operated in a fashion such that its NAV will equal, in dollar terms, the dollar price of spot natural gas or any particular futures contract based on natural gas.

United States Oil Fund, L.P. (USO) options will open with strike prices of 40-65 and position limits of 25,000,000 shares. The options will trade on the January expiration cycle. The specialist will be CTC, LLC.  The investment objective of USO is for the changes in percentage terms of the units’ net asset value (NAV) to reflect the changes in percentage terms of the spot price of West Texas Intermediate (“WTI”) light, sweet crude oil delivered to Cushing, Oklahoma (“WTI light, sweet crude oil”), as measured by the changes in the price of the futures contract on WTI light, sweet crude oil as traded on the New York Mercantile Exchange that is the near-month contract, except when the near-month contract is within two weeks of expiration, in which case the futures contract will be the second to nearest out month contract to expire, less USO’s expenses.