Rowan Companies, Inc. (Rowan) is a provider of international and domestic contract drilling services. The Company also owns and operates a manufacturing division that produces equipment for the drilling, mining and timber industries. It provides contract drilling services utilizing a fleet of 21 self-elevating mobile offshore drilling platforms (jack-up rigs) and 26 land drilling rigs. Rowan's drilling operations are conducted primarily in the Gulf of Mexico, the Middle East, the North Sea, offshore eastern Canada and in Texas, Louisiana and Oklahoma.

ENSCO International Incorporated (ENSCO) is an international offshore contract drilling company. Its offshore contract drilling operations are integral to the exploration, development and production of oil and natural gas. As of February 15, 2007, its offshore rig fleet included 43 jackup rigs, one ultra-deepwater semisubmersible rig and one barge rig. In addition, it has three ultra-deepwater semisubmersible rigs. Its operations are concentrated in the geographic regions of Asia Pacific, Europe/Africa, and North and South America.

Diamond Offshore Drilling, Inc. (Diamond Offshore) provides contract drilling services to the energy industry worldwide and is also engaged in deepwater drilling with a fleet of 44 offshore drilling rigs. The Company's fleet consists of 30 semisubmersibles, 13 jack-ups and one drillship. The Company offers a range of services worldwide in various markets, including the deep water, harsh environment, conventional semisubmersible and jack-up markets. The Company provides offshore drilling services to a customer base that includes independent oil and gas companies and government-owned oil companies.

Petrohawk Energy Corporation (Petrohawk) is an independent oil and natural gas company engaged in the acquisition, development, production and exploration of oil and natural gas properties located onshore in North America. Properties are concentrated in East Texas/North Louisiana, onshore Gulf Coast, and in the Permian, Anadarko and Arkoma basins.

Oceaneering International, Inc. is a global oilfield provider of engineered services and products primarily to the offshore oil and gas industry, with a focus on deepwater applications. Through the use of its applied technology capabilities, the Company also serves the defense and aerospace industries. The services and products the Company provides to the oil and gas industry include remotely operated vehicles, mobile offshore production systems, built-to-order specialty hardware, engineering and project management, subsea intervention services, nondestructive testing and inspection, and manned diving.

Atwood Oceanics, Inc. is engaged in the international offshore drilling, and completion of exploratory and developmental oil and gas wells and related support, management and consulting services. The Company's operations include eight offshore mobile drilling units located in five regions of the world, such as offshore southeast Asia, offshore Africa, offshore Australia, the Black Sea and the United States Gulf of Mexico. It also manages two self-contained platform rigs.

Marathon Oil Corporation (Marathon) is engaged in exploration, production and marketing of crude oil and natural gas worldwide. The Company operates in three segments: Exploration and Production (E&P), which explores for, produces and markets crude oil and natural gas on a worldwide basis; Refining, Marketing and Transportation (RM&T), which refines, markets and transports crude oil and petroleum products, primarily in the Midwest, the upper Great Plains and southeastern United States, and Integrated Gas (IG), which markets and transports products manufactured from natural gas, such as liquefied natural gas (LNG) and methanol, on a worldwide basis, and is developing other projects.