ONEOK 's Energy Services operation focuses primarily on marketing natural gas and related services throughout the U.S. Energy Services showed an operating income increase of $26.5 million .
The U.S. Energy Services derives more than 84 percent of its earnings from the physical marketing business .
ONEOK 's Energy Services operation focuses primarily on marketing natural gas and related services throughout the U.S. Energy Services , which derives more than 84 percent of its earnings from the physical marketing business , showed an operating income increase of $26.5 million .