A. A. Production Inc. ABB Vetco Gray Inc. ABN-Amro Bank Acadian Gas Pipeline System Accell Natural Gas Co. Act Operating Co. Addison Energy Inc. Advantage Energy Services Ltd. AEDC U.S.A. Inc. Aeon Energy Corp AES Electric Limited Afren Plc Agrium Inc. Air Products and Chemicals Inc. Alamo Resources LLC. Alarado Resources Albans Energy Alberta Natural Gas Co. Ltd. Alberta Resources Venture Inc. Albrecht & Associates Inc. Alet Inc. Algonquin Petroleum Corp. Allegro Operating Inc. Alliance Resources PLC. Allied Natural Gas Corp. Alpandra Corp. Alpha Land Services Alpine Resources Inc. Alsask Energy Services Inc. Alta Mesa Resources Inc. Alvarado, Smith, Villa & Sanchez Amarado Oil Co. Inc. Amegy Bank Amerac Energy Corp. American Coastal Energy American Energy Partners American International Petroleum American Oil & Gas Inc. American Penn Energy Inc. American Refining and Exploration American Trading and Production Ameriwest Energy Corp. Amni International Petroleum Development Ample Resources Anadarko Petroleum Corp. Anderman Operating Co. Inc. Andex Resources LLC. Anglo Suisse Inc. Angola LNG Ltd. Antara Resources Inc. Antrim Energy Inc. Apache Corp. Apex Oil & Gas Inc. Aquila Energy Capital Corp. Arawak Energy Corp. Arc Resources Ltd. Arcapita Bank BSC. Archean Energy Ltd. Arco Oil & Gas Co. Arena Energy Argonauts Group Ltd. Arjon Enterprizes Ltd. Armstrong Oil & Gas Inc. Arrow Exploration Co. Arthur Smith Corp. Ascom Group S.A. Asher Associates Inc. Asociacion SMC-Pacifpetrol Santa Aspen Energy Corp. Atco Electric Atlantic LNG Co. of Trinidad Auburn Enterprises Aurora Gas LLC. Avalanche Energy Ltd. Aviara Energy Corp. Axem Resources Inc. |
A/D Holdings LP. Aberdeen Petroleum (USA) Inc. Abu Dhabi National Oil Co. Acadian Resource Co. Acon Investments Adams Resources Exploration Corp. Adobe Energy Inc. AEC Oil & Gas Aegis Energy Inc. Aera Energy LLC.. Agip Petroleum Co. Inc. AIG Energy Inc. Alabma Electric Cooperative Inc. Alamo-Palace MP 59 LLC. Alaska Oil & Gas Conservation Alberta Ltd. Alberta Oil Sands Inc. Alberta Special Waste Management Alcoa / Alumax Alexander Energy Corp. All American Oil & Gas Inc. Alliance Energy Corp. Allied Energy Corp. Almeida Partners Ltd. Alpar Resources Inc. Alpine Resources Inc. Alrosa Alta Energy Corp. Alumax Inc. Amalgamated Explorations Inc. Amaranth Advisors Amen Properties American Appraisal Associates Inc. American Energy Operations Inc. American Exploration Co. American Liberty Oil Co. American Oil Services American Premier Underwriters Inc. American Resources Offshore Inc. American West Oil and Gas Corp. Aminex USA Inc. Amoco Production Co. Amvest Oil & Gas Inc. Ancell Energy Consulting Inc. Anderson Oil Co. Andrews & Kurth LLP. Anshutz Exploration Corp. Antero Resources Corp. Aoco Operating Co. LLC. Apco Argentina Inc. APF Energy Inc. Aquila Energy Resources Arbol Resources Inc. Arcadia Exploration and Prodcution Arch Petroleum Inc. Archer Resources Ltd. Arctic Slope Regional Corp. Arg Resources Inc. Aries Resources LLC. Arlington Energy Partners Arpetrol Inc. Arroyo Energy Investors Arxa International Energy Inc. Asgard Resources Ltd. Ashland Exploration Inc. Aspect Resources LLC. AT&T Capital Athena Energy LLC. ATP Oil & Gas Corp. Aures Energy LLC. Autry C. Stephens Avatar Petroleum Inc. Aviva Petroleum Inc. |