Utilize the input text as a context reference, choose the right relationship between 'Williams Companies' and 'natural gas' from the options.
Options: product/material produced, manufacturer, chairperson, original broadcaster

Within this article: Details on U.S. natural gas pipeline projects, including those from major companies such as Kinder Morgan Incorporated ( KMI ), TransCanada Corporation ( TRP ), Spectra Energy Corporation ( SE ) and Williams Companies ( WMB ).
product/material produced