TULSA, Okla., March 25 /PRNewswire-FirstCall/ -- Williams (NYSE: WMB) has begun processing additional volumes of natural gas at its Opal, Wyo., processing plant following an expansion completed by Willbros Mt. West, Inc., a business unit of Willbros Group, Inc. (NYSE: WG).

The new volumes are being produced by affiliates of Shell Exploration & Production Company in southwestern Wyoming's Pinedale Anticline.

Alan Armstrong, senior vice president of Williams' midstream gas and liquids group, said, "The combined efforts of the teams from Willbros, Shell and Williams delivered an industry solution that provides reliable and efficient service for Shell's growing production volumes for many years to come. This is a joint success for our companies and Wyoming's export capacity."

The expansion involved the construction of a fourth cryogenic processing train at Williams' Opal facility. The unit, which has a processing capacity of 350 million cubic feet per day, was built and will be owned by Willbros Mt. West.

Williams commercially and physically operates the new unit under a long- term agreement with Willbros Mt. West. The terms of the agreement provide for revenue opportunities to both Williams and Willbros Mt. West.

The project boosts Opal's cryogenic processing capacity from roughly 750 MMcf/d to more than 1.1 billion cubic feet per day and the total inlet capacity, including blending, from approximately 1.15 Bcf/d to 1.5 Bcf/d. The plant also has the ability to recover approximately 56,000 barrels per day of natural gas liquids.

"Our long-term relationship with Williams allowed us to create a unique structure for the expansion of processing capacity at the Opal plant," commented Michael F. Curran, president and chief executive officer of Willbros. "Willbros' financial capability combined with its expertise in the design and construction of gas processing facilities enabled us to work in partnership with Williams to develop the project within a very short time frame and within budget. We have also had a strategic goal of increasing the long-term and predictable components of our total revenue stream and the Opal facility is a step in accomplishing this goal."

From the Opal plant, gas can be delivered to markets throughout the West Coast and in the Rockies via connections to three interstate natural gas pipelines -- Colorado Interstate Pipeline, Kern River Pipeline and Williams' own Northwest Pipeline.

About Williams

Williams, through its subsidiaries, primarily finds, produces, gathers, processes and transports natural gas. Williams' gas wells, pipelines and midstream facilities are concentrated in the Northwest, Rocky Mountains, Gulf Coast and Eastern Seaboard. More information is available at www.williams.com .

About Willbros

Willbros Group, Inc. is one of the leading independent contractors serving the oil, gas and power industries, providing construction, engineering and other specialty oilfield-related services to industry and government entities worldwide. The Company's World Wide Web site can be accessed at www.willbros.com .

Portions of this document may constitute "forward-looking statements" as defined by federal law. Although the company believes any such statements are based on reasonable assumptions, there is no assurance that actual outcomes will not be materially different. Any such statements are made in reliance on the "safe harbor" protections provided under the Private Securities Reform Act of 1995. Additional information about issues that could lead to material changes in performance is contained in the company's annual reports filed with the Securities and Exchange Commission.

SOURCE Williams; Willbros Group, Inc.

CONTACT: media relations, Brad Church, +1-918-573-3332, or investor
relations, Travis Campbell, +1-918-573-2944, or Richard George,
+1-918-573-3679, all of Williams; or Mike Collier of Willbros Group, Inc.,
+1-713-403-8038
Web site: http://www.williams.com
http://www.willbros.com