Willbros Group, Inc. is a global engineering and contractor company based in Houston, Texas, United States. It is listed in the New York Stock Exchange. The company operates in the field of energy infrastructure services. Willbros provides engineering, procurement and construction, such as refinery turnarounds, pipeline construction, pipeline integrity management, GIS consulting and other specialty services. Willbros was founded by William Brothers Company in 1908. It is organized under laws of Panama. It was reorganized as a public company in 1996. Originally, it was headquartered in Tulsa, Oklahoma. However, in 2000 it moved its administrative headquarters to Houston, Texas. In 2006, Willbros discontinued its operations in Nigeria and Venezuela, although in 2004, Nigeria accounted about 25% of companys global revenue. This decision was due to political instability and the militant attacks in Nigeria. Before making this decision, nine Willbros' workers were taken hostage by Nigerian militants. On February 28, 2005, Willbros Group Inc., said that it was restating financial reports from 2002 on and forecast 2005 earnings far below Wall Street estimates. The adjustments would lower 2002 profit by $900,000, widen the 2003 loss by $2.6 million.